If you trust your assessment of the girl--if you think she's likely not to appreciate, or, worse, to be disappointed in Sprout's gift--then I think I might urge Sprout to put her creative efforts just into the card. Handmade gifts are something I think people appreciate more (generally speaking) when they're a little older--say, ten, eleven, twelve--when they have some notion of what it represents in terms of time and dedication, and when they may have more interest in the process and appreciation for outcomes beyond just surface things.

Sometimes little kids can be surprising, though, and she might turn out to enjoy whatever Sprout made as much as she'd enjoy a store-bought thing, even just for the novelty.

Parties for young children are as much (seems to me in retrospect; not sure I thought about it at the time) about the interactions among the adults and the overall culture of the group. Thinking about that can be a guide, too.

Can you buy something that Sprout can add to or decorate or put together as a gift?

Well, can't weigh in with my own experience, but in puppy training, the road of least conflict is often preferred. :p

I think it sounds like a lovely compromise.

I agree with you and Sprout but with a caveat.

Let's see if I can help/muck things up by putting it this way: A gift is about what one thinks the gift receiver will like the most and not about what the gift giver likes the most.

For me, since both kids are still pretty young, I'd totally go with the do both option, handmade gift and a store bought one and using this as a Teaching Moment about learning the happiness of pleasing the gift receiver more than yourself too.

I'd go with a bought gift as well as the home-made one, because the most important thing is empathy with the receiver.

I suspect that explaining that thinking of what the recipient wants is not a bad thing.

And it may be nicer for Sprout to learn from you that for some people, handmade things have value and for other people, bought things have value. Not as a "we have to buy a present" but as a "here's something to think about" for the very reasons you are posting. Do you think Sprout is smart enough and ready to understand that there are two sides to every gift opportunity? :)