https://support.apple.com/en-us/HT211768

You kinda can, as long as someone in your household with an iPhone can set up the watch for your daughter as a family member. Someone has to have an iPhone in order to deal with setup and any access control and some features won’t be available without a companion iPhone, but it might be sufficient for your daughter’s needs. Then she can sign into the same iCloud account on the iPad. I can’t speak to how well it’ll behave between those two devices on the same iCloud account and how well anything like handoff or continuity will work because I haven’t had need to try it, but if you wanted her to have a watch and no phone I think this is the only way to do it right now.