Josie wants to be able to send her son money while he's at college. Leo says the kids are using Paypal's VenMo. Facebook Messenger is also going to add payments, as is SnapChat. She should check the commission charges, though. The best way is to establish a bank account that she can pay into.
The chatroom says that Square's Cash.Me is great and charges no fees. Apple is also going to add payments to its Messages app.
(Disclaimer: Square is a sponsor)