Yes. Your free over 75 licence will also cover any person(s) younger than 75 living at your main address, until the licence expires.
Anyone aged 74 or over and receiving Pension Credit can apply for a free over 75 TV Licence. Pension Credit can be in the name of the licence holder, or in their partner’s name if they’re a couple and live at the same address.
If you or your partner don’t receive Pension Credit you’ll need to continue to pay for your licence.