Need to vent about my mom

So when night time comes around my mom becomes a very annoying bitch. I love her dearly but she drinks to much vodka and ice or vodka and juice. Very little juice. Than she complains about every freakin thing. Like crying over spilled milk. It is just meh at night between me and her and her and my dad. Like tonight I simple was so excited that my friend who was married lost her husband over seas he drowned while trying to get a drop box for supplies that landed in water. She is doing very well with her daughter and she is either fostering 1

Or 2 kids and I thought that was amazing with help from her family and friends. And I told my mom and dad and my mom was like really she is by her self fostering two kids and hers. I'm like (ya) and she like oh I bet she doesn't work. I'm like no she does at Best Buy with my friend. And than she like oh that's so great being sycastic and all bitchy about it. And saying oh well I see a lot of red flags flying from this. Really a friend can't foster one or two kids and her 7-9 year old daughter. Like she picks and than bitches about something I think is good.

Any thought on what to do or how to talk to her and explain this bothers me. Please comment.