Joint ownership sole mortgage advice

Hello all, I hope you're all well.

I was wondering if you could offer some advice on whether the below is possible.

My wife's nan passed away and has left her property (mortgage free) to five people. My wife now has 1/8 of the property and estate. She would like to use this as a deposit to buy some the property,. Two of the beneficiaries would like to leave their shares in, both 1/4 each.

The property is valued at £230,000. Her share of the property is worth £28,750. And so effectively needs to get a mortgage of £86,250. One mortgage broker said its not possible as there will be three people on the title deeds but only one with a mortgage.

Is there a way of getting around this? I'm sure this situation is really common so there must be a solution?

Many thanks in advance