Yeah, Molly will adjust.

She didn't have an issue with our last foster (also female) but that one was only 7 months old when she arrived and they wound up playing together all the time (that foster was with us for 6 months regaining her health after being diagnosed with dermatomyositis).
Ms. B is not very interested in the other dogs other than harassing my biggest (Barley) constantly if there is food around. She's quite dominant in that
sense. He doesn't take her very seriously and just avoids/ignores her when she does it, even if she rushes him. She's only 6 pounds but of course with dogs, they don't pay much attention to size.
Compounding the ...... is that her heart medication is a diuretic, so she has to pee frequently. We have a ton of flat cloth diapers and just keep an eye out for puddles. If she pees, we throw a diaper on it to soak it up, then run a WetJet with vinegar/water over it after it's cleaned up. It just takes a second.
Ms. B was supposed to be a hospice foster with very little time left, but once the stress of her shelter stay/vet stay were over and she was in a home she's really bounced back and I wouldn't be surprised to see her go for another couple of years.
This was her a few days ago - a vast difference from the sickly, frail little thing that arrived 3 weeks ago!
https://www.facebook.com/photo.php?v=10152106701988339&set=vb.666303338&type=3&theater