Have you considered giving tokens; Boots, elder GS can always buy toiletries there or Smiths (magazines, Newspapers and some computer prepherals. Neither shop is licensed so it cannot be spent on alcohol.
Having said that, I would not give anything to someone who cannot be bothered to thank me for my gift and I would be quite prepared to point that out if it was noticed one GC was getting a gift and the other wasn't.
On a personal level, both GC are still at primary school. I would always give something to direct descendants, no matter what age, but a niece has just had her 18th birthday. I gave her a cheque considerably more than ther normal sum and said that from now on I will send cards but no more presents.
Being moved along by someone who "wants your place".
Is there anyone who still thinks that Israel's actions in Gaza are justifiable?
Why Planning Your Burial Ahead of Time Can Be a Gift to Your Loved Ones