Lifetime trusts and remaindermen entitlement

We have a lifetime trust in favour o the surviving spouse over the entire of the deceased estate, the trust allows access to capital as well as income.

A letter accompanying explains that his first priority is his spouse and ensuring she is adequately provided for.

Our query is whether the remaindermen would have any grounds to query how the trust money was used as this effects their entitlement at the end. for example, how much was paid out to the life tenant or if a property was sold whether the sale price was adequate.

My understanding, especially in this case, is that the remaindermen are just to inherit whatever is left when the trust ends.

thanks in advance