Ignoring bills

[tentmadam]

My sister died recently owing myself quite alot of money(we inherited a house together).My family have paid the rates,electricity bills and repairs to the house .We were instructed to send copies of all bills to the solicitor.My sisters family are now ignoring the bills.Can they do this?They have obtained letters of administration and have approached us about selling their part of the house at their price to us.Which we are going to challenge after having our own survey and valuations done.Help please.