Live in Mother-In-Law

My mother in law lives with us, small 4 bedroom 2 bath house. Her bedroom is the only one downstairs with her own bathroom. Wife and I, as well as two kids rooms are upstairs. She first moved in to help her financially as she left her abusive long-term bf, now she is stable enough to move out.

The thing is, I love her living with is. She is helpful around the house, helpful with LO's, and we always have a babysitter when we want to have a night out, or as we call it, 'grown up night'.

Just wondering if this is completely abnormal or if anyone else has similar experience living with extended family?