Should I become a legal guardian?

My daughter Esther's friend Sarah was kicked out of her house by her aunt who is her legal guardian. I guess Sarah pulled too many teenage antics and her aunt has had it. Sarah is no angel, but having been in foster care since she was 7 and being abused before that, I feel she needs a lot of love and guidance right now.
We took her in for the last two weeks. I already have 4 of my own children. I want to do the right thing.
The aunt wants to surrender her guardianship and then send Sarah to Florida to live with her dad who she is astranged from and another aunt and uncle as well.
Sarah is 16 and wants to finish high school here.
The aunt got upset with us for trying to help and she says we are making it worse.
I am a little nervous for taking something this big on and am a novice here. Anyone been a foster kid or a guardian or a foster parent?

Sarah and her aunt did give the judge our name to be considered for her legal guardian. We will meet with a court officer on Thursday. I pray that God will open or close this door and His will be done. I want to help and it is up to the authorities now. Sarah will be 17 in 10 months and be emancipated then.

You have a very kind heart. To take on a 16 year old is a tremendous task. How does your family feel about all this?
I am in more or less in the same situation. Everyone deserves a chance, so give her one with all the rules laid down. Sounds like this may be her last chance.

My mom fostered but it was for little kids. You can always foster her but lay down the rules and tell her like it is and make sure you are firm as well as nurturing.

I have guardianship of my nephew who is 5. I do think that you should consult your family, particularly your daughter, to find out how they all feel about it. It is a huge responsibilty. Also, when I was 14, one of my sisters friends came to live with us due to problems within her family (she claimed that her stepfather abused her and her mother didn't believe it). It was very hard for all of us ( I have 2 sisters). I don't know that I would say I regret that she moved in with us. It was just hard. She was older than me by maybe 3 years, and younger than my older sister by probably the same. She moved in when she was 18 (so she was her own guardian), and moved out when she was 22. There were a lot of problems with her not wanting to follow the rules, and when whe moved out it wasn't on good terms. We have not spoken since she moved out. I understand that you want to help this girl, and I commend that. However, you need to seriously consider the effects this will have on your family ( I remember feeling like she was more important than I was). I'm not saying don't do it, I'm just saying you need to weigh it all out with your family first.
Good luck