It seems to me your impulse to see that your children get some gifts from your wife is very well intentioned and I respect that.
On the other hand, I think giving anyone a gift on behalf of someone else without that person's knowledge and agreement could easily be seen as patronizing and lead to resentment.
Is this something you could talk to your wife about?
I agree--worth talking through. Could save a LOT of drama later.
sg Love is PATIENT, love is KIND, LOVE never fails / DB since 2001