In this case this twin will bring disaster Spoiler
Mc made emperor and his brother the general fall in love with her Emperor proposed ( he said he would return her sister to her family if she accepted to marry him because she said he was already her sister husband and she didn't want to have the same husband than her sister) and general confessed his love Novel ends with her still a military man but with a permit that let her enter the harem so she could visit her sister. In the end she is happy hugging her sister and thinking she will be happy with her sister and not think in the two boys (open ending)
In this case this twin will bring disaster
Spoiler
Mc made emperor and his brother the general fall in love with her
Emperor proposed ( he said he would return her sister to her family if she accepted to marry him because she said he was already her sister husband and she didn't want to have the same husband than her sister) and general confessed his love
Novel ends with her still a military man but with a permit that let her enter the harem so she could visit her sister.
In the end she is happy hugging her sister and thinking she will be happy with her sister and not think in the two boys (open ending)