Weddings bring out the absolute worst in people. I wonder what the "Aunt's" son and family think of getting a forced invite to a wedding of someone they don't actually know? If it were me I'd be mortified and it would be a polite decline anyway and a telling off to my mother.
I'll never forget trying to plan a wedding. Every little thing was a battle and every single time I said how DH and I wanted it, the in-law's acted like I was bloody bridezilla.
My MIL went crazy at our wedding trying to invite pretty much every single member of her extended family and friends who my husband either didn't know at all or hadn't seen since he was a small boy. She demanded personal transportation for them all too. (We couldn't afford wedding cars for even the B&G and in the end, I only had one because my mum's friend offered to chauffeur me in his vintage car)
Then to add insult to injury, she threw a massive tantrum at the fact that I had MY aunts and uncle invited but not hers. Thankfully my DH, stunned, told her that as the bride, mine should be invited and as he was the groom, his aunts and uncles would also be able there. Not our parent's aunts and uncles.
She insisted that my husband's sister and 2 nieces be my bridesmaids (forgetting that it's bride's choice and as we and my parents were financing it, could barely afford even my own MOH sister and my 2 DDs). I told her if I had DH's sis and 2 kids, then I would have to extend the offer to my own SILs and nieces on my own side, making it a minimum of 12 bridesmaids!
She went so far as actually cancelling our evening buffet caterers as she was a friend of theirs and wanted them to relax and attend the wedding instead (they owned our venue and were catering the entire event - which we were paying for) So who was to make the replacement buffet? Why MY aunts of course. One nursing an end stage terminally ill husband and the other 3 travelling between 4 to 8 hours to attend the wedding. She assumed that they could travel up and spend the evening and next morning pre-wedding cooking and baking for 200 guests. Suuuuure.
She also declared that it should be me to drive her around on the morning of the wedding to her hair and make up appointments. (Despite the fact that her own DD would be there and quite able to drive her around as I of course, would be busy getting ready as the sodding bride!)
According to her I was not to have my own step father and step mother (both lovely people and financial contributors to the wedding not that it matters at all) to sit at the top table with my own parents as they would outnumber her and her DH. I simply told her that with 6 months notice she is free to separate from her man and find new partners for both if being outnumbered bothered her so much. 
There was a whole crazy list of things she demanded and you know what? She got maybe two. Such as inviting SIL's friend and a very small handful of people we didn't know at all to the evening. That it. She stropped and kicked off but we just politely and consistently reminded her that her own wedding was over 40 years ago and should she wish to invite all and sundry to a wedding of her own design, then a vow renewal could be arranged.
Stay strong OP. It's YOUR wedding. Just keep reminding people of that. No one would demand you change your kid's pirate birthday party theme to princesses because their own child would prefer it so why do so many people assume they can tell you your wedding should be to their tastes too?