With Zara gone, Alita didn't do anything for a while and calmed herself down. Zara's impulsiveness had been an eye-opener for her, if she had not come and acted the way that she did, Alita wouldn't have known the attitude that these families have.
It also showed her that she was still too weak and anyone can just trample on her and try to take away things that she owns.
She was considered to be powerful but, in this city, and planet, it was just her alone. Her relationship with Aaron was one created for benefits and she couldn't really consider him a genuine friend because of that.
If Alita wanted to make a name for herself and make herself more powerful, she needed to become stronger and have more allies. The best way to achieve that and the fastest way was to get married.