My daughter had a child out of wedlock. She gave my grandchild the dads last name on the birth certificate. Who has the ultimate say in the child's upbringing?

Since both are listed on the birth certificate, legally they both have equal authority until there is a court order to determine custody of the child if the two are no longer living together.

You really have not given enough info, are the two still living together, if not is there a court order for custody and child support

She needs to go file for primary custody and child support. Then they can go before the Judge and work out visitations for the father and so forth. Generally the one with primary custody will have to inform and include the other parent about any doctors appts, school activities and any decisions such as surgery, etc...
Basically don't leave them in the dark.

She needs to go file for primary custody and child support. Then they can go before the Judge and work out visitations for the father and so forth. Generally the one with primary custody will have to inform and include the other parent about any doctors appts, school activities and any decisions such as surgery, etc.....
basically don't leave them in the dark.
In my view she has ALL rights as well as primary custody until the Judge says different...

In my view she has ALL rights as well as primary custody until the Judge says different...



And my view is the same as GV's view.