Lyme? Anyone have experiences with LO and Lyme disease

Babe is 1. This was just a red mark days ago... last Friday my in laws were over with their dog.. he's a very outdoorsy dog, they live surrounded by bush and fields and stuff, and has brought many ticks over in the past. So he is a likely culprit.

But, she was Shirtless in our yard that evening and the mosquitos got both my kids. Only this Bite changed and since yesterday looks like this for two days.

I DO plan on taking her to Dr tomorrow but curious what the process is IF it is Lyme? How do they test? What else should I watch for? She is acting totally normal, the mark isn't warm to touch. It's just there.

Is this a lifelong thing that could cause issues in something? I'm totally unfamiliar with this

But want to know what to expect or hear some similar experiences. Thanks