I stay in the U. K. my daughter took a lease on a flat for 6 months but she has decided she no longer wants to?

If she has a fixed-term lease, she is liable potentially for the cost of the entire 6 months, unless the landlord finds another tenant

you may have the option of giving 1 months notice and leaving without having to pay the rest - to be sure, she'll need to check the terms of her tenancy agreement

It depends entirely on the terms of the lease. The sooner that you speak with the landlord the better.

Last one we had, the landlord had to let us stay for 6 months , but we had the option of leaving after 3 if we wished.

Normally yes, her Landlord can insist she pays the remaining rent. Your daughter can always get in touch with the Landlord and see what he would be willing to do though.

Blessings x

A contract for 6 months is just that. That's what her signature committed her to. So, yes the LL is entitled to payment for the full term in the same way that she is entitled to reside for the full term. Simples.