To stay friends, or not to stay friends??? That is the question!!

So I have been friends with this girl for a long time we were never best friends or super close but grew closer over the last 3 years. Last year she got engaged and was married this last Friday. I was so excited for her and her fiancé seeing that we were all friends and they asked me and my boyfriend to be in their wedding... I always thought these two were the perfect couple never argued always seemed happy. Being that we were never the best friend type we never really talked about personal problems in our relationships with our significant others, which is fine I like leaving my personal stuff between me and my boyfriend... Anyways about a few weeks ago I learned that This girl had cheated on her boyfriend, then learned it was more than one occasion, obviously he forgave her and took her back. When I found out she was a cheater I lost a little respect for her.. Now I'm at the point where I'm finding out other things that make her not trustworthy and don't know if I should continue the friendship or and it now how can you have a friend you don't trust or respect.. During her bachelorette party I found out she asked another girl to make sure she behaved herself because there was a guy she was falling for and flirting with.. I found this out after the party but my response was "really you need a babysitter to stay faithful to your fiancé?" I know the situation has nothing to do with me personally, am I over reacting about not trusting or respecting her anymore? Also she has no idea I know all of this she thought her secret was safe.. I just don't know what to do remain friends and hope she never tries to screw me over or slowly end it now..

I have very strong morals when it comes to marriage and I believe that you should only marry someone if you know you want to be faithful and spend the rest of your life with them. Marriage is not a joke and if you need a baby sitter to stay faithful you probably shouldn't be getting married.. what would happen next time if you don't have someone to watch you? is it their fault they weren't there to make sure you stayed faithful?