T.N.
Hi M. (my daughter's name), it's likely a HUGE transition which will take more than a week or two to 'get used to'. Frankly I rocked my own daughter to sleep til she was nearly 4. You daughter is only 2 right? She's gonna need you extra to get through this new family structure.
Perhaps you can go back to rocking her for now? Maybe ask her whether she would like you to rock her or rub her back, or something else.
EDIT: Sometimes is helps to give her something of yours to sleep with. Something that smells and feels like you, a favorite sweater, tee shirt, bathrobe etc, it's important to tell her it WILL help her sleep. Also be sure you tell her often how you're always there for her first, she may feel threatened by you're sleeping with someone else now, and the new kids in the house. Make sure she knows no matter what, it'll ALWAYS be you and her together!
Take her to buy a 'lovey'. Nothing expensive, just a little stuffed animal you can tell her will help her sleep at night.
When she wakes up (a new house, new situation is scary), put her back to bed, rub her back for awhile, rock her, remind her she has her new 'lovey' that makes sleeping nice.
I'm sorry poor Mamma, feeling totally drained, but this two shall pass, she WILL settle in.
Good Luck!!