You should not give anyone else your personal identification numbers (pins) or passwords. By giving away these details, you’re breaking your provider’s rules. If money goes missing from your account, they could refuse to refund it.
If you want someone to be able to access your savings and investments, make the arrangement more formal. For example, you could set up a third-party mandate or joint account. When you set up a third-party mandate or joint account, the person helping you can have their own card and pin.