Congratulations! I'm sure every grandparent can relate to what you are experiencing though not in the double sense. You're sure going to have some fun.
Our grandson, Joshua is now four and is really into Thomas & the engines in a big way and when I found a train ornament pattern in last years holiday issue from Creative Woodworks I decided this was going to be this years ornaments from Nana. I have made & painted 14 so far (and even put their right numbers on them, I hope!!). I'll make enough for each day of Dec so he can open one a day till the big day.
Now I have to think what's appropriate for Hayley who is 20mths.
As they say grandkids are God's gifts for surving teenage years.
