Siblings and Birthday Gifts

So to start with as a rule I don’t give my kids presents on siblings bdays for obvious reasons. Kids are almost 2y f and almost 3y m. I’m planning a mall bday for my daughters big day next month. This includes doing a build a bear.

Now I’m wondering do I let my son make a bear too or no as this is one of her bday presents? I want him to understand it’s her special day but also this is kind of an activity, not just a toy. I don’t see the harm in letting him do it, but I’m not sure. Any advice?

Not sure if this is important, but I do plan on getting her one or two other presents if she sees something she likes. We will also be playing in a bounce house play area and riding the carousel both of which my son will also get to participate.