To top up her phone you can to here: https://mobile.lebara.com/nl/en/all-in/c/prepaid-all-in and select a plan. The next screen you can click “guest”, so you don’t have to use an account or her account. You can enter the number 0620996846 Then enter your email address and continue. The third screen will let you pay via credit card, say Visa, MasterCard or American express.