<human>: Together for 2 years and she (may) recently moved into my house a few months ago and all is well. I have two sons who are 28 & 25 years old and two 23 year old daughters and she has no childern. 

Now she has a sister (sarah) in the states (we are in canada) who is 30 and 6 months pregnant with her second child. She is unemployed and was living with her boyfriend but they had a falling out and now she wants to move to be with closer to family. she is being kicked out soon and since we are the closet to have help with her baby and other child.

She has never had a steady job which  makes me very worried. 

This is the tricky part. I dont want her here. She could stay a few weeks but she said she feels the need to stay for a year min to get set up with the baby. She asked if I would be willing to look after the baby since I work from home while she is out looking for a job since my gf travels alot for work it would just be the sister her kids and I. 

No. Fuck no.

Im almost 50 and ive done this shit four times but I dont want her to uproot her life to come here and she would have no other place to go if I had to kick her out.

My gf has asked and said its up to me, she wants to help her sister but knows all the problems with it. They are close. Apparently the bf (ex) is kicking her out and has been physically abusive ...

I'm feeling the pressure. I'm not sure how to approach this situation. I don't want to be that asshole; to burn bridges, I like the peace and dont want tension but I dont want 3 more people moving into my house for year or more on my dime. Esp since I have my own kids and grandkids that visit. I need help on how to approach it. She just came to me a few hours ago with this so I havent had much time to think about it.

Can you succinctly summarize the text in 1-3 sentences?
<bot>: GF sister (getting kicked out) wants to move in for year or more into my house with her children so they can get settled.