I don’t know what to do

I’m a one of 4 daughters and my mother is a single parent, we’ve always been close but sadly as I’ve gotten older me and my eldest sister have kinda been left out. My youngest two sisters who are currently over the age of 20 literally spend time with my mother nearly every day. Obviously I’m a stay at home mum and my partner work nights so I ask for company sometimes as it can get so isolating and I usually get left on read. My eldest sister is a nurse so is busy constantly and I never expect her to come over as she barely gets time on her own but my other two sisters don’t work or nothing.

I found out months back as well they’ve been going out places together without me and my eldest sister, when asked they’ll lie everytime. It’s gotten to the point where if I found out they’ve gone out I don’t get phased but recently it’s constant. I’ve literally begged before while suffering with pnd for help and just company an Ill get ignored or left on read. I feel sad and I know whenever I’ll bring it up to them I’ll get called petty or sad or pathetic which has happened before. I don’t know what else to do atp.

It’s also the same with our children, my sister has two kids as well and I have two but my mother will literally take her children out constantly while my eldest is at home with me and her 3 month old sister. I’ve noticed for years she’s always favoured her children over mine as even when I’ve asked for help with the kids I won’t get no reply for hours but whenever my sister asks for help they’re there in an instant… I feel so pathetic even typing it because I know I’ll get called silly