I OWN land JOINTLY WITH A SISTER AND SHE DIED AND I PAID FOR FUNERAL, CAN I SELL HER HALF TO RECOUP?

She lived in a mobile home on it. later she married. in her will she left her half to him if he continued to make payments on and it( and i let him,) otherwise i was do do whatever i wanted to do. he recently moved and i am having trouble getting him to sell. also taxes are due. i was told i am responsible. i had to pay for her funeral as he couldn't. can i put the land up for sale without his signature , keep my half and use her half to pay funeral expenses? the land is now paid in full.