My husbands ex aulted him how long do they usually hold people for?

Ok I will try to make this short. Me n my husband went to a parent teacher conferene. His daugher's mom is the custodial parent he is the non. But he is involved and has frequent vistations. Anyway when we pulled up to the school his daughter came running from the side of the school(she lives across the street from school) and she was balling. We pulled over asked her what was wrong and after 5 minutes of not bn able to talk she said "My mom is cussing and yelling again and she is scaring me." We asked her why. She said" my mom asked me when I got home frm school today if I wanted to know why she was so mad I said yeah and she said because I got court papers today." She was getting court papers because my husband is taking her back to court for modification of custody. His daugter's well being is at stake. DFS (Department of Family Services) has been involved. The cops have already been involved. Anyway, she said her mom went completely crazy yelling screaming cussing and threatening her and told her she didnt want her anymore to just go live with us. She told her to get out of her house so she said thats why she went to the school to wait for us to show up at the conference. Well we told her to go inside the school with us. When we were done we went outside her mom was standing outside on the phone. Her mom yelled GET OVER HERE NOW, LETS GO!! She told her that she was scared and jumped behind my husband. Her mom went on saying no she isnt scared she is just in trouble so i askd her well why? She said none of your business but she then stated "What she needs is her *** beat! Well that scared the child so she ran to our car. It all ended up my husband had to put his arm up to block her shoving because he was holding my two yr old and this lady just wouldnt stop and listen a minute. I believe she may had been drunk. Anyway she ended up putting her hands on him by grabbing his face and pushing it. I put my arms in between them to get her away from my 2 yr old and she grabbed my arm and twisted. She called the cops on US saying we were in the wrong. Well we got in the car and took his daughter to the police station ended up signing complaints on her thinking maybe it would teach her a lesson with all this crap she has put us n their daughter through which mind you has been like this for the last 4 yrs. Anyway she ended up going to jail but the cop stated that of course she is saying he was pretty much beating the crap out of her so she may file a complaint and seeings how they dont have the same story that he could possibly go to jail later. Can they do that? I mean this happened last night and he hasnt been arrested yet so is there a chance he may be? Also my stepdaughter is really worried about whats going to happen when she gets out how long will they hold her. Sorry so long. Any info?