Am i too selfish to think this way?

My sister moved in with us 1 year ago 'cause she divorced and need help with job and a place to stay. I was pregnant with my 1st baby at that time. The house we ( my husband and me ) bought with my parents have 3 bedroom. So we had no room for the nursery, baby sleep with us in my room. Now my baby get older, i want he has his own room. I'm thinking about tell her to move out to her apartment. Am i right to ask her that or am just heartless to treat a fmily member that way? Since she lives with us. She does help with the bills, we didnt ask her to pay alot cause she has no kind of money saving. But i figured after a year living with us and 250$/ month she gave us for bills she can able to move out on her own right? She makes about 1300$/ month with no car payment.

Any advices help. Thanks