girlsfriends parents trying to stop me from seeing kids

My girlfriend and I have two kids together, my son is 11 months and my daughter is almost 3. Before my son was born we had a fallout, my girlfriend and I were in an argument, the result ended with her calling the police and saying I hurt her and my daughter, I was taken to jail for domestic violence and child abuse. It was not true, I never laid a hand on ether one, I had threatened to take my daughter from her and that was how she responded. The district attorney dismissed the charges, and we did not have contact until last month, since then I have been seeing my kids and her every day, the problem is that her parents are telling her that they will take our children from her if she continues to see me, she is also being told this by social workers that work with her and the kids from a Regonal center her in California. The question is can she lose the kids just for seeing me, and what can i do to fix things

[tbyte]

How old are you, and how old is the mother?
If you are legally adults, her parents can do nothing to take the children from her, or from you.
Do not let them push you around or bully you.
Is there a child support order in place? Is there a visitation order in place?