I can relate, as i am one of 10 kids! I'm right down the bottom too, number 7. So yes sometimes i do feel asthough i have to compete with my siblings.
But at the end of the day, i'm happy with everything. My parents have their lives, plus 10 others to worry about, so certainly it can be busy.
The thing i have learnt about having a large family is that, family will always be family. No matter what you guys go through, or say to eachother there is a bond there that will last a lifetime.
I would talk to your mum about how you feel. It may go well for you, and she may realize what she has done all of these years. Or, things could remain the same. Atleast you have given her something to think about.
My father and i have never got along, and just recently i lay everything out on the table.I wrote all my feelings down first, then asked if i could have a moment and read it out. I told him things i would have never dreamed of teling him.Things i have carried around for years on my shoulders that made me resent him.after i told him, Nothing changed. He just blamed me for all his actions for all of these years and nothing was solved.
But within myself, i feel soooooo much better because now, i don't have to carry anything around with me. My dad heard everything i said that night, and he has something to think about. In ways, we are closer. Because i hold nothing against him now. Yes, he blamed me, but i feel as though we have something to work with now. Instead of me just being hurt and wanting more from him.
Your mum is your mum. She certainly does love you and care for you and your family, otherwise she wouldn't ring you. Just find within yourself the strength you need to talk to her about it. You have nothing to lose at the end of the day. And the 2 ways it will go are not too bad. You may be a tad disapointed if it doesn't go the way it planned like i was. But it is certainly not a reason to hold back anything