I have a daughter by a british woman. Me and her relationship didn't work out. Can she just take our daughter?

-My daughter was born in America. Me and the woman currently live together and it has been this way for 2 years. Our differences have proven to be stronger than our love. And she threatened to leave the US with my daughter to go back to England. She is not a US citizen and will likely not be able to return to the US (immigration Issues) . I will be so heartbroken to not have my daughter in my life until she is old enough to know the truth. And that is if the mother even lets her know about me when she gets older. I don't want to lose my daughter someone please help! There is no abuse mentally or physically in this relationship before anyone says anything outrageous. Neither me or her has a job right now. I cant afford a lawyer and we are both not working so in a custody battle who will win?Does your "girl friend" have a passport for the child yet? If she does not, then you can take the child and apply for a joint passport, where the child is actually on your passport. This results in you HAVING to be with the child when she leaves the country. However, if your name is not on the child's birth certificate, this may result in your being unable to get a passport for this child.
I'm not a lawyer so I can't give you complete advice but I don't think your situation looks good. Custody battles are almost always won by the mother. Its just assumed that a woman will always take better care of the child than a man. Try researching your situation more online. Wish I could help you more, good luck.