a little lon but please could any one give some info or anything else that would help me and my husband?

ok i been married to my husband about six month now we have 16 month old baby girl. now my husband does has another child that 31/2 years old and she before me and my husband got together. he has a baby mother who's basically draining him of money which make it hard on me because i have to pick up the slack and i barely make enough to cover the extra. the whole point of me getting a job was to supplement his income our play money as he say. well he baby mother get almost $400 a month from him in child support, now mind you she on welfare and she get ssi check. she always calling say that the lil girl need this and she needs that. she also call both of his parent who are not together and get things fro them for the child. they send clothes shoes. with all these things she get from them and my husband she also got him getting her a bedroom set for the girl and he pay that every month in addition to the child support so all in all he dishing out about a lil over $500. she won't let him see when he wants to get her, she claims it because of me because i won't sit down and talk with her. i tried to adult once before and met with her and she stared me in my face looked me up and down and then walked away and this after i said hello to her. i was wonder does anyone have opinions or advise to give me to help my husband because it wearing us down and we be fighting because of money issues. because he dishing out extra money to her. is the a legal way he can do something to decrease the money he gives due to all the help she getting from his family. oh and he is in military.