Is it normal my mum encourages my sister to drink, sex, etc.?

So a little backstory on my mum first, she's basically a typical bogan who gambles her money away constantly, drinks nearly every week to the point she can't even balance and needs someone to drag her and hold her up while she vomits, jobless and relies on the government for money, and when meeting men she mostly just likes to use them for their money/to take her places and doesn't really care about them.

Since me and my sister have been living with her, my younger sister being 16 when we first moved on my mum has been pressuring and encouraging my sister to do what she does. She buys my sister alcohol and lets her get drunk and is currently encouraging her to date men (many who are older then her like 6 years older or in their 20's but my mum doesn't care) the moment my sister meets someone online my mum is trying to get her to tell that man to come over, have drinks with them, etc. and my mum has said she doesn't really care if my sister decides to have sex with these older men. So is it normal? I'm disgusted by my mums behavior