How long is a proper time to mourn my estranged husbands death?

There is no proper time. It's not your fault what happened and those people who talked just have nothing better to do with their lives than make nasty comments about others. Just ignore them. If you want to go out and dance then you go and dance. Who says you should be at home mourning? It doesn't mean you'll ever forget him just means that you're getting on with your own life as you should be. Love and grief is funny like that. It works different for everyone so if you feel it's time you want to go out and do what you want then it doesn't matter what those kinda people think. They're sad and pathetic. Just do what you feel you're up to and forget about others. Only you'll know when it's time to move on and if it feels right then just go with it :) X