I want to purchase a watch for my kid and do family setup. Can they message someone with an android phone on the watch without being paired to their own phone?
With Family Setup, your family member who doesn't have their own iPhone can use their Apple Watch to do things like make phone calls, send messages, and share their location with you. Since Family Setup requires An Apple Watch Series 4 or later with cellular, you should be able to send and receive SMS text messages.
Set up a family member’s Apple Watch - Apple Support
With Family Setup, your family member who doesn't have their own iPhone can use their Apple Watch to do things like make phone calls, send messages, and share their location with you. Since Family Setup requires An Apple Watch Series 4 or later with cellular, you should be able to send and receive SMS text messages.
Set up a family member’s Apple Watch - Apple Support
SMS/MMS requires a paired iPhone, as the Apple Watch cellular radio is LTE "Data" only, which means it does not have the standard cellular features that SMS uses.
See:
Use your Apple Watch without your iPhone nearby - Apple Support
2) To receive SMS, MMS, or push notifications from third-party apps on your cellular Apple Watch, your paired iPhone must be powered on and connected to Wi-Fi or cellular, but it doesn't need to be nearby. You also need to be signed in to iMessage on your iPhone to use Messages on your watch.
Your child does not have a paired iPhone, so just Internet based messaging services.
When you set up a watch for a family member can you send SMS text messages or just iMessages?
