I have found this to be very true and it has happened to us - when people think you have money or items, they are your best friend. If you are having hard times - you have no friends. If you don't want to come right out and say "no". Then always tell anyone that you have to consult with your kids and let it go at that.
The good thing that came out of that phone call is that now you know what type of friend she is and always be careful.
Best of luck to you and your children as you move to a new time in your lives.