Meanings of unmurmuring resignation in English

I have wondered at your fortitude and disinterested interest in others,- Ihavewondered at your Christian submission, your unmurmuring resignation, and I wonder still.

Sternly, unremittingly, since the fair July night when Richard had left her nearly five years earlier, she had schooled herself into unmurmuring resignation and calm.

Mr. Ogilvie was amused at Armine's notion of unmurmuring resignation, but he added only, "Which would be much assisted by a little exertion."

"I hope so, but with my health there seems nothing left for me but unmurmuring resignation."