Apple ID funds & family sharing

Hi!

So I’m a member of family sharing, my sis is the organizer and I’m like “parent”

anyhow it’s kinda annoying to always send money to sis card then buy trough it.

I kind of read that there is gift card but I kind of don’t wanna use this method as I don’t wanna add that much money at one time. And on Polish site there is 100+ only

the add funds function in the AppStore app looks better. But would I be able to pay for it trough my own card or would it still be charged trough sisters?

or is there a way to send myself a smaller amount on gift card?

ive read so many post yet none had an answer for it :(