Is it tacky to put money in a child's birthday card instead of buying a present?

[Sallystyle]

DD has a birthday party to go to tomorrow, I forgot all about it until today.

Is it tacky to put money in a card? The child is 6 if it makes a difference. I don't really fancy walking into the city today as it is an hours walk both ways and I don't really want to drag all the children out feeling lazy

No at all!

I often put money in a card - surely the kids prefer this?

DS turned 6 at the weekend and was so chuffed when he got money in 6-7 of the cards from his school friends

Much better then some of the presents that have clearly been 're-gifted'.

Wow that's ungrateful but I had a couple this weekend. Haha