Brother in law's wife has decided to be bridesmaid

[titzillaa]

long time lurker, so I know what the consensus is on in law wedding threads, but I have an inlaw wedding dilemma!

so me and DP have been together on/off for six years and engaged for two. we've finally set a date for the wedding and started planning, I've decided on eight bridesmaids (my 2 x Dsis, my cousin, four friends and DP's sister who I'm very close to). however, DP's sister texted me earlier announcing that she's pregnant (due january) and so she's not going to be able to be a bridesmaid, as she doesn't want to have to worry about fitting into her dress and breastfeeding a newborn on the day.
fine - I have absolutely no problems with that and was very happy for her, and my plan was to just have seven bridesmaids which is plenty. however, DP just got home from work and said he'd had a text from his brother's wife (she's very very close to his side of the family) saying she can happily 'take over' from SIL?
firstly I don't see why she needs to 'take over' as it's not as if there were any specific duties that SIL had. secondly, brother's wife has already complained about the date of our wedding (it's the day after she gets back from a music festival), the venue (it's the one that her and BIL were looking at for their wedding reception last year, but it was booked and they ended up finding one they liked more) and said the colour of the dresses was ugly (they're khaki). she's not said any of this to me but instead to MIL/SIL/BIL who have relayed it back to us.
however if I tell her I don't want her to be a bridesmaid she'll cause a massive fuss (she has very few close female friends so I was a bridesmaid at hers last year - more out of filling space than intimacy) and DP's family will take her side, I know it.
AIBU to be pissed off?

Let her kick up a fuss and look like a fool of that's what she chooses to do. That is not your problem. "Thanks anyway, but I already have my bridal party sorted." That's all you need to say.

I was a bridesmaid at hers last year - more out of filling space than intimacy)

Just curiosity: If you don't like her (much) why didn't you decline to be her bridesmaid ?

It’s a bit forward of her to ask, but given you were her bridesmaid last year it’s not completely u.

If you were having 2 bridesmaids it would be out of the question imo but... 8 bridesmaids... just let her do it, she’ll be lost in the crowd anyway.

Just say no that's ok you're sorted. If she kicks up a fuss say you realised 7 bridesmaids is enough as it is.

Just call her out on her misgivings about your plans. Say you wouldn't want to inflict such an awful dress on her...

Another one wondering why you agreed to be bridesmaid for someone you don't like?
I'd just say "thanks for the offer but I'm going to stick with 7" and repeat.

Wait, you were her bridesmaid and didn't offer her a spot in return? That's a bit shitty tbh OP, sorry. Especially as you know she hasn't got many female friends.

Just let her do it. At the end of the day with 8 bridesmaids anyway (😳) no one will really notice at all.

Whatever you do don't say you're sticking with 7 because of money, she might offer you pay for her bit!

Sorry you lost me at 8 bridesmaids.

*to, not you

she's not said any of this to me but instead to MIL/SIL/BIL who have relayed it back to us.

This helps no-one.

As she is married she can't be a bridesmaid.

I assume that the post of maid of honour is already filled? So no vacancy

Don't reply. Although I'm a little bit as you don't seem keen on her, so baffled as to why you agreed to be her bridesmaid.

I mean, them telling you what SiL said helps no-one, but can only cause trouble.

8 bridesmaids? Really?

I'd go with the thank you for your kind offer but it's OK, I hadn't got a specific number in mind

EIGHT BRIDESMAIDS!!!!!!!!!!!!!!!!

we were on better terms last year (we're not even really on bad terms now, we're just very different people and don't spend that much time together), so at the time I had no problem. during the wedding planning she turned into a total bridezilla.
maybe I should have returned the favour from the start but I just really don't feel close to her now and I would have much rather had my SIL.

8 adult bridesmaids? So you were happy to be a bridesmaid for her?

Until I read that you were her bridesmaid last year I was all for telling her no thanks but my being her bridesmaid you have put yourself on shaky ground for making any claims that you 'aren't close' and 'don't get on'

If it will cause WW3 with the ILs if you knock her back then the easier/kinder thing may be to go along with it

Oh FFS, you were always going to have 8 bridesmaids. Who cares if she's the eighth? You'll barely notice her in the khaki satin scrum!

Why is the whole family relaying shitty things others have said back to you? Weird way to go on IMO. I'd be just as about the ones telling you all this stuff.

As above -
You were her bridesmaid and you're having a whole bunch of them so what's the big deal?

YANBU, after her nasty comments I wouldn't want her as BM.

Tell her that given her unhappiness with your choice of bridesmaid dress, venue and date of wedding, you don't think she would bring the necessary joy and positivity to the role of bridesmaid.

Or do what I would do and tell her you've already asked someone else. If she asks who, say you can't say yet.

She thinks she’s doing you a favour. In the interests of family unity I’d let her. I presume she’d be quite closely involved anyway.

"oh, no need, as we were really hoping you could help with xxxx"

(Insert job eg: reading/confetti guardian/ help with cake testing)