The Sisters of St. Martha are selling their motherhouse in Charlottetown. ((CBC))

The Sisters of St. Martha are selling their motherhouse in Charlottetown and more than 5.5 hectares of adjoining property around the Confederation Trail.

The congregation has owned Mount St. Mary's — a 90,000-square-foot residence with 92 bedrooms and several dozen bathrooms — for 46 years.

"This beloved building of ours has really outgrown who we are now," said Sister Rosemary MacDonald, the congregation leader.

MacDonald said when the structure was built in the early 1960s, the congregation had approximately 160 members. Now, there are 64 members in the congregation, and only 37 of them live at Mount St. Mary's.

"Over the years, there's a lot of more possibilities for women," said MacDonald. "There's a lot of avenues or fields available to them to seek vocation."

The four-storey building has been well maintained and is in good shape, MacDonald said.

The sisters said they hope whoever buys the property respects the tradition of the building.

"We would like that it would, I suppose, somehow carry on who we have been over the years, who the Sisters of St. Martha have been to the people of Prince Edward Island," MacDonald said.

"We have been involved in health care; we have been involved in education, and in social work."

Potential buyers have until Feb. 12 to submit their proposals for the land. The congregation is also asking for a smaller residence to be built on the property for them.