If she is centered solely on bitcoin then Ledger nano s would be enough. Pros: S is ~ half the price of X. She can even buy the family pack of 3 pieces for the price of X and use those extra ledgers from the pack as back-up devices. Besides the functionality of S model doesn't depend on the build-in battery simply because there is no such item inside the case.
Or just wait for another Ledger promo wherein his\her friend can buy Ledger Nano S for half or 30% less price than the original single price of approximate $70. I am not just sure when they are going to have another sale as of the moment, I am just lucky to avail their product with a 50% less promo last bitcoin halving LOL.
@OP, Welcome to the cold side!