I'd move her close by but NOT in with you. By close by I mean same neighborhood, same street even but not the same home.
Why? Many very important reasons, starting with both 9 year old children. They are BOTH going to be reeling from this development. Don't shove it into their 24/7 lives.
Next reason is that if you move her into your home you CANNOT legally kick her out after she establishes residency. She will have tenant's rights and you can't make her leave.
I am a rental property owner. Last year one of my tenants moved his ex wife into my rent house out of kindness. After she had been there 2 weeks, things went sour & he couldn't kick her out. As in the cops required him to give her access to the house since after a couple weeks...she's a resident!!
That resolved by me giving notice of eviction of everybody...including my 6 year tenured renter and their minor children for breach of contract/moving an unauthorized adult into the property...but I was going to allow my renter to move to another property I owned which was several blocks away without his ex wife.
Thing was his kids attend the school directly across the street, so moving was going to totally uproot his kids. In the end his ex wife chose to move out when she understood that I was serious about eviction & she was going to really disrupt her kids lives.
My renter was very lucky I had that kind of leverage. He came to me for help with the matter. He still lives there.
Do NOT give her that kind of leverage over you in your own home. It has serious implications for you that you may not realize.
Be wise. Keep her separate but near. Use your 9 year old's welfare as the excuse if you must but DO NOT move her in with you.
See how she reacts when you propose this idea. Anything other than an understanding attitude will tell you everything you need to know. She should pay for her own place near you. NOT live with you.
