I was raised in a reform household and growing up in I was taught to read Hebrew during Tefila with a havara sephardit. After being chozer beteshuva and spending many years in yeshiva (many of which were charedi) I became accustomed to using a havara ashkenazis. Now that I am living in Israel and raising my children here, I will be sending them to school which they will also be raised to learn Hebrew with a havara sephardit. Do I need to stick to the havara ashkenazis or can I go back to my original sephardit in order to not confuse my children?
Firstly, all pronunciations are kosher (even for allowing a woman to marry through the saying of chalitza, so how much more so regarding prayer)! Although there is importance to keeping one’s family’s customs, the most important issue here is that in most communities in Israel the sefaradi pronunciation is clearly the accepted minhag and really everybody davening in such shuls should do as the others, and not be different, to avoid arguments (Psachim 50a). Although many have said that in large cities today all customs are accepted, it really depends on the shul. In most shuls in Israel, and even more so in schools, there clearly is (!) an accepted minhag for havara (pronunciation), which should be followed, and that supersedes one’s father’s previous custom.