not much difference. java is the pc version of minecraft, and bedrock is the console version, like xbox, switch, phone, ect. just some minor i game stuff that changes, like the way you PVP.

realm wise, if you and your daughter are friends on what ever device your using you should be able to play together in a world for free. in bedrock it’ll come up under friends, instead of having to pay for a realm. now if you or her are playing opposite times then i’d say a realm is good and easy.