C.O.
S.:
Do NOT call CPS unless you have sufficient evidence. If you are keeping a spreadsheet with the times you have her, you should be able to account for bruising, diaper rashes, etc.
Your BF is the ONLY one to make the full custody decision. It only becomes an issue for you if you are his wife. GF?! Nope. No say.
Toddlers get bruises all the time. Oh my - my daughter could be playing and fall, out on the playground and messing around? Yes, even at 2 years old. They are still new to walking.
If the bruises are in ODD locations (top of the arm (finger prints, buttocks (hand shaped) or face - ASK the toddler how she got the bruises - DO NOT coach her. Just ask her "Jana how did you get the boo-boo?" DO NOT say "Jana did mama hit you?" DO NOT give her leading questions - have her tell you the story.
Diaper rashes can be common in children. if the mother is not changing her as often as you do or she's eating differently with her mother than with you - it could be food sensitivity, laundry detergent sensitivity, etc. TALK with the mother - find out what she feeds her, how often she changes the diapers, what her schedule is like - if you are turning into her primary care giver, then these are all things you need to know in order to take better care of their daughter.
If your BF is hiding his head NOW, IT WILL NOT CHANGE in the future. SO YOU need to decide if this is who you want to spend your life with. If he hides his head about THIS - what about other issues? What if the car payment is late? All of these issues are IMPORTANT, if he hides his head and ignores it - you never know what you could walk in on one day if you married him....(or walk out to...no car because the car was repo'ed)...seriously. think about the long term with this one....you already have your rose colored glasses off, now you need to do the HARD stuff - if he won't stand up for his daughter, what will he stand up for?