What parts do you find confusing? Maybe i could shed some light ヾ(❀╹◡╹)ノ~
It was never about her getting out of a bad marriage, its about changing the past so she, the ML and secretary-ssi don't die. Yeah but she married the new guy who had his own evil sibling and family problems LOL! So their problem intertwined
Yeah but then the whole thing about the Mother wasn't really dead, something about paintings from some long lost uncle or grandfather? The guy's parents were all so killed by the same woman but I'm not sure why but I'm pretty sure it's about some obscure money problem, also the girls real father but then her real father is a crook but he just wants a picture of her? And I'm trying to figure out, so she's pregnant even though we never saw them have any kind of relations but then they say she's probably pregnant with the other dude that used to be her husband from the past life, even though I've not seen them hook up. Because I thought he just liked her and he did it because he was such a simp and wanted one day to hook up with her but didn't they did? I didn't even know they had physical relations I thought she was just a cock tease. So yeah I'm just confused where all this is coming from and from where because if you don't show the Smashing scene, and I know it's tasteful not to but still you know there's still implications, then I don't know who's getting smashed and I don't know why a lady within catch another woman's house on fire and then adopt the baby of the mother she supposedly killed?
Okay, let's start slow. I think you've got some of the character mixed up. The FL, Han Yi Joo, was seperated from her mother after the fire. Her mum was told she had died in the fire (can't explain why, not too sure). She ended up in an orphanage and was later adopted by her Biological dad and this first wife(adoptive mother). My understanding of events is that, Han Yu-Ra(evil stepsister)'s mum Lee Jong-Hye, worked in that house as either a maid or housekeeper, and is a black widow (marries and kill for benefits). Clearly the Biological Dad, Han Ji-won, is trash, because he was having affairs that produced children. His father, FL's grandad, didn't approve of the FL's mother and so she decided to raise the child herself. Buy Jong-Hye (evil stepmum), wanted the Han Ji-won for herself, knowing that he will want FL's mum back if he new of the child, decided to kill her first. Didn't work out as planned, because the dad ended up marrying FL's adoptive mother (probably set up by his dad). I do think they were able to have kids, so years later, they adopted FL, Yi Joo. Yi Joo's life was great, her adoptive mother was loving etc. But the housekeeper (Jong-Hye), posioned the Mum and she died. Afterward, she brought Yu-Ra home and claimed that she was Han Ji-Won's child with faked documents proving DNA and fake documents saying Yi Joo was not his bio daughter. I think she either slept with the dad around the time that the FL was born or tricked him into thinking they slept together, and that Yu-Ra was the product of the affair. FL's dad was forced/ or chosed to marry her because of that.
Now the evil step mother's story: Lee Jong-Hye, was together with Yu-Ra's biological dad but left him probably because he's unsuccessful and broke. She then got with Secretary oppa, Yoo Se-Hyuk's Dad, becuase he had money, was a an artist and had money. She probably married him and poisoned him also for the money and deed to his life's work and gallery. Which is how Se-Hyuk ended up in the orphanage with the FL Yi Joo. Her next target was Han Ji-Won who was still married to the adoptive mother at the time. Her plan was to kill the grandfather, Han Ji-Won and FL, so she can inherit the company via marriage and "blood" through Yu-Ra. But she failed to kill Yi Joo, as she survived the posioning.
Yu-Ra (evil step sister), is pregnant. It's implied that she's had a sexually relationship or one night stand with ML's step brother, probably when she seduced him. But when her mum asked her if she knows who the father is, it means that she's been sleeping around just like her mother did. I think the baby might be Yi Joo ex-fiancee, as who she was also seducing to marry Yi Joo. Now she's also faking, that it's ML's brothers baby because she need to secure a future for herself. She's basically just repeating her mother's mistakes ┑( ̄Д  ̄)┍ I get why you're confused, as they didn't show this but it's just implied. Sex is not really shown unless it's that kind of webtoon, even in Kdramas it's mostly implied. Although nowadays some are really explicit.
I don't know if that explains it well, but i'm sure the Kdrama will be clearer/easier to understand (〜 ̄△ ̄)〜 but yeah, this is how i understood the story so far.
No you did a great job explaining it. Thank you so much and I appreciate these notes because I was so lost in the sauce. So I'm getting an idea what's going on. It's just that wow, this plot is so convoluted. I mean, I wonder how they're going to pull this off when they make it into a live-action kdrama
I think you might be thinking of "marry my husband" she was terminally ill and stuck in a loveless marriage w shitty in-laws and an even shittier husband. here her lifelong "best friend" and husband were having an affair for years and killed her (albeit on accident) when she finally found out. then she went back in time w the knowledge of her past life.

Is this man okay ?? That's a funny choice of wording seeing as he attempted to kill his son AND daughter in law! But the company is where ahjussi draws the line LOOOOOOOOOOOOL!
the brother is such an idiot, he had all the tine and money to plot his misguided revenge but couldn't hire a PI to find out what happened to his mum or where she was(unless she died)??? He eally could have had a loving childhood(providing that the step mum wasn't those bitch ones), but he chose violence. (〜 ̄△ ̄)〜 can't even pretend to feel bad for him