Here is what I think you should do.
Tell her you love her.
Tell her she is responsible for her decisions. This is a serious decision. One that would be best made when she is absolutely sure.
Assuming she knows about your doubts, tell her some questions about the org are coming up for you.
But you trust her to find her way. Actually you are in a similar process of finding, learning.
A serious commitment like this should only be made with total certainty.
Make sure she knows you care about her, that is the number one, baptisim or no baptism.
Alot of times the commitment is made to seek approval from withholding parents and friends.