Does she have an Android or iOS phone? Samourai Wallet should be fairly easy to use if you set it up for her. It supports RBF which could come in handy in case she sent a transaction with a low fee (although it shouldn't happen). Blockstream Green Wallet should be even easier to use. It even supports hardware wallets but I don't think it's necessary in this case. Both wallets are available only on Android.

I would not recommend the mobile version of Electrum. I had a few problems with it, mostly crashes while trying to bump a transaction fee.