Transferring ISA's between people

ISAs are Individual accounts and we each have our OWN allowances each year. Any money that goes in to her ISA, having not previously been in her ISA, is going to count against her 2019/20 limit of £20,000.

You can take the money out of your account into your bank account and then you or she can put it in hers. Whether that incurs fees or charges depends on whether the ISA provider has any costs for withdrawing money.

For example if you have an investment ISA there may be cost to sell the assets you hold or an administrative fee to close the account. If it is a cash ISA but fixed term, there may be an interest penalty for closing it early. You can't 'transfer' to another person to dodge the fees, because you want to invest under her allowances so it has to go in as fresh new money from a bank account into her account.

But if it is a simple cash ISA account there may not be any fees of course.