Would there be alternative sources for births?
Unless a baptismal record can be found showing her full birthdate and not just her christening date - then no
Could it be that the baptism records could had been destroyed/damaged?
Perhaps somebody with local knowledge of any such event can help with that one. The likeliest is lack of transcriptions. You are very much dependant on the willingness of volunteers to transcribe entries from the registers
Whilst it completes things to have the birth/baptism info - being realistic - apart from her actual birthdate - what other info will you obtain from a birth cert or baptismal entry that you don't already know from census entries?
The birth cert will give her parents names and mothers maiden name - already known
Her fathers occupation - already known
The baptismal entry probably won't show mothers maiden name so you will just get the date of baptism and her parents names and possibly her actual birthdate but that's not guaranteed