Lumpy vein (?) on neck?

Does anyone else’s little one have a lumpy vein (?) stick out at the base of their neck from time to time?

So hard to get a picture of it, but in person it has a blue/grey colour to it so I assume it’s a vein?

I’ll be chatting to her PCP but we can’t get in until later in the week. So I’m trying to figure out if it’s pretty normal or something I should be concerned about.