You won't be able to get full custody. You will always lose and cost tens of thousands. Unless you can prove an unfit mother...
What you can get is joint custody obviously. You have no choice but to fight for extra time in court. I told my wife, no divorce unless I get 50% of the time with the boys. We are splitting the week, every week. Stay strong.
Remarried 6 mo S 12 S 13 S 16 SD 12 SD 16 SD 17 SS 19