My father passed away 3 months ago, am i allowed to partake in a shabbos meal at my Shul with my husband and family and the rest of the Shul families?
During the week this would not be allowed, however for Shabbos the rule is different, since we are not noheg aveilus in a public way. Therefore, it would depend on the situation. If you’re not being there is very obvious, that you are meant to be there, and you aren’t because of the aveilus, then it would be permitted, otherwise not.
Yaavetz 2-180, Pischei Teshuva Y:D 391-2, Gesher Hachayim 21-8(12), Daas Kedoshim 391-4, Poskim.