I don't have a guide, but it would be fun to make one. BE CAREFUL though. You don't want to send real Bitcoin to a testnet address. Have her try a testnet only wallet like Padawan first. I don't know any iPhone testnet apps.🫤 https://github.com/thunderbiscuit/padawan-wallet She can use the seed signer with Nunchuck. Just change the network settings to testnet instead of mainnet. Be sure to change it back when you're done. Let me know if you have any questions or need some testnet 4 sats.