Friendship advice/questions?

I went out with my friends for a girls nite, and one of my friends got mad at me because she wasn't invited and said to me that she could have requested the nite off. But, my friend is always broke and everytime I go out I always end up paying for her always and she told me that she didn't want to go out with us because she didn't want to owe me. Also, I told my friend that someone invited me to their party. My friend is married with 2 kids and my other friends as well as me are single. Every time my friend gets money she spends it right away and I have advised her to save money when we got out and by the time we go out, she is broke. I am sick and tired of it and I have told her how I felt and she still doesn't get it. Any help is appreciated.