Hi Monique – that is an incredibly difficult situation. It is one thing to become Catholic from a Jewish background when only you have to keep the secret, but it is quite different with kids.
G-d’s utterly limitless and incarnate Wisdom will deliver you, though no one knows how yet. I know a person whose graces after Baptism were such for several months that immediate family were given the blessing of accepting their conversion on account of absolutely glowing in terms of mood and life changes during those months of grace (extended family was another matter, however). One can never hope too much.
In terms of being Jewish and Catholic very generally – from my experience I still celebrate high holidays (it gets tricky when Good Friday and Pesach align if you’re in the Roman rite, but you may ask a dispensation if you are inclined), and intend to continue. I appreciate lit candles on Fridays and I do not feel any obligation to lose any aspect of my identity. However, I grew up without much religion and without many of the religious customs, but this much has been my experience – however, it has not been with kids.
May Our Lady Seat of Wisdom and Yeshua’s most wise foster father Yosef HaTzaddik obtain by their intercession the wisdom to act as G-d wills you to.
Will pray for your family and ask prayers on your behalf!