Maid of honor being a nightmare

Hello, so I picked my sister as my maid of honour. She is older than me and my engagement brought a lot of negative emotions up for her as she was due to get married a few years ago and broke it off with her fiancée. She then started dating a woman who really is lovely and a great match for my sister.
A week after my engagement my sister proposed to her girlfriend who then proposed back.
When I told my sister the date we had planned she started kicking off big time saying I’m unfair because she wanted that date. And instead booked her wedding abroad a week after mine (knowing we would be on our honeymoon which was already booked). Her wedding now has been postponed to December because of restrictions.
- She was telling me the dress I had chosen is awful and the one she’s picked for her bridesmaids is much nicer - she’s told me I better not get pregnant because she doesn’t want me to look fat in my bridesmaid dress at her wedding (despite her not even having asked me to be a bridesmaid) - she wouldn’t plan my bachelorette and at one point said she’s not coming because I didn’t invite her partner (which was nothing against her partner but you go on a bachelorette to get away from your partner and let lose) - another bridesmaid planned my bachelorette and my bridal shower and she refused to come to my bridal shower. - After buying all the dresses and shoes. I asked for bridesmaids to pay for them to be altered and give them back a week before the wedding as I want to take them to the venue the day before. that way I can be stress free in that respect knowing no one is going to forget about them ... she sent her dress with my mum to the bridal shower but not the shoes. She’s over my way this weekend at her holiday home (about 30 mins but won’t drive them to me // I’m super busy as my wedding is in 5 days) I asked them to drop them off at my in laws which is a 10 minute detour on her way home. She won’t as she’s sick of “running around after me”.- I’m paying for all bridesmaids to have hair and makeup done as I want them all having the same hair up. She’s kicked off saying she will pull the pins out as she doesn’t want hair up. - I’ve asked bridesmaids to take care of their own manis and pedis but asked them to go with something natural like french polish or neutral or if they can’t get a mani pedi just give their nails a neat file and clear polish. She bought a nude colour and a neon pink polish. She sent me a pic of both and said I’ve got the choice in what she wears but the nude makes it look like she’s got dirty builders nails ... I said I don’t want the neon and she can fine basic nails it is then. - another one I almost forgot. When I went to try on wedding dresses she just sat there with a face on the whole appointment. Telling the staff at the shop about her wedding. I went for the first one I tried on cos I loved it and after she said; yeah if you didn’t buy it I would have.
And now she’s kicking off because me and HTB have decided against her doing a speech.
She is acting like I’m being too much and trying to have a perfect wedding which is never going to happen and I need to chill. I’m trying to plan the day I want in detail. Do you think the fact I’m super upset about her behaviour is valid? Because my mom is acting like nothing is happening because she won’t take sides.