Status credits never expire in the same way right? (aside from the annual reset)
Lifetime Status Credits don't expire but the annual tally (the annual tally is used for qualifying for temporary status) is reset at the end of each membership year which is based on when the flyer joined the QFF program.
Also if you transfer the points to you you could always use them on your kids without having to do a points transfer back (e.g. you can request a points upgrade for a family member).
imo as the parent you bought the flights and it would be fair for you to keep the points.
Note that the minimum for a points transfer is 5,000 points so you may need to transfer some points to the child in order to be able to transfer out the child's balance.
The only concern with you keeping the points if you keep your own account active would be if you expect to have a tally above 600,000 (the maximum to transfer out a year) and think there's a high risk that you're likely to pass away soon. Upon your death your account is terminated and all your points forfeited.
A trusted family member may be able to transfer your points before QFF becomes aware of your death but if you have more than 600,000 points (the maximum to transfer out a year) some points will be lost.