Throwaway account, just in case…

I (25F) share the responsibility of caring for my Nan (85F) with my mum. It’s been this way for about four years now, as my Nan is pretty much bed-bound. We split the duties between us. Obviously, my mum has cared for her all her life, but once I started driving, I was finally able to take a more active role, though I’ve always helped however I could. My nan has 4 children but me and my mom are her main careers.

My parents went on a two-week vacation recently, boasting about spending upwards of 20k. Before they left, I was growing increasingly concerned about my Nan’s memory and suspected dementia. I brought this up to my mum, but she said she didn’t want anything to interfere with her holiday and specifically asked not to be contacted if anything happened with Nan—she said she needed a break and didn’t want to know. I thought this was selfish, but her choice and I respected her wishes.

Last week, I decided I couldn’t wait any longer and contacted the doctor. He agreed her behavior was worrying and arranged a memory test. She scored very poorly and has instantly been referred for further dementia assessment.

Now to this week, while looking after Nan, she opened her bank statement in front of me, and I noticed the balance. It was about £2k less than what I’d last seen 18 months ago. For context, my Nan receives a decent pension—around £1.7k a month. She’s pretty much bed-bound, eats very little, has no mortgage or debt, and minimal bills. Over the past 18 months, she would have received roughly £30.6k into that account… but yet she had 2k less than when I’d originally seen it.

I understand she has living costs, but they’re incredibly low. I’ve been doing her groceries for the past month and it’s only about £300 a month. Meanwhile, I earn roughly the same as her monthly pension, and I managed mortgage, bills, car, social life, and I’m still able to save. So I was surprised. I planned to bring it up with my mum once she returned and had settled.

Today, my mum came back from vacation and visited Nan. Apparently, Nan asked her about the money and accused her of taking it. Mum called me furious, saying I’d been “in Nan’s ear.” For the record, I’ve never discussed money with Nan. I was hurt that she instantly thought I was the instigator in this all. Other people do visit my nan, so someone else could’ve seen the statement and flagged it with her. Or, when showing her the statement last week she could have flagged something herself.

I unfortunately couldn’t hold my tongue and told my mum that I did find it strange how much money had disappeared, especially since £1k had been withdrawn just this month “for Nan’s expenses.” Now my dad is saying I’ve accused them of stealing and called them thieves—something I never said. I never accused them of anything, only asked if I could get an understanding of what is going on with nans money. But I do think it’s odd that Nan, with such minimal outgoings, is unable to save any money. Also, for context I’m not written into the will and everything will be going to my mom and aunts, so I’m not benefitting from any of this.

AITA for finding this all suspicious and speaking up?