Yes, a week they use some stamina potion something.. Sebella (not sure of the name, lol.) her maid even saw the potion when ML was going outside and it got awkward.. lmao
And if I'm right Sebella married that Alven dude, that was a surprise. Also Rosie became doting Aunt.. She got her redemption and her grandfather actually isn't either good or bad he didn't care seeing her children fight for the throne he didn't meddle himself too. But also became a doting grandpa at the end..
There's still no official English translation of the novel but here are some fan translations and spoilers here..
Link: https://forum.novelupdates.com/threads/the-princess-imprints-a-traitor.115909/

First of all I loooooveeee Michaaaeel!!
Their first time was so wild they did it for a week and it was so intense.. Damn.. and the confession is so damn sweet it's giving me diabetes..
I also love the part where Michael remembered the 1st timeline his so precious and Eve knowing that Michael had love him in the 1st timeline (her master told her, the one who took back the time) Daaaammnn aaaahhhhh love it!!
(ノ≧∇≦)ノ
Also they had 3 children. uwu