Um... So I just found out my Mum used to smoke pot...?

I wonder what other wild skeletons she's got in her closet

Well, at some point in time I guess we all realize our parents aren't the perfect people we always thought or hoped they were. How lucky you were to have a traditional mom who stayed home and baked cookies. That is who is really is as well. Just like you, your mom has had many chapters in her life. She was once a crazy teen and a young woman in her 20's. She wasn't thinking about her future children then just like you aren't thinking about what your future children might think about you. She was just in the moment being a teen. You sound very, very fortunate to have had a mom that was able to provide for you what sounds like a stable upbringing. Of course it feels weird that she may have smoked pot but that was in her youth..... did she remain a habitual pot smoker or was it just something that happened when she was young. If you gave you positive childhood then try not to judge her about what she did as a teen/20 something. Anyway it seems like she left that in the past (as she should have) and in the present is a really good mom. There are a significant number or people on here who can't same the same. Focus you attention on what she has done well and be grateful for that!