to not let neighbour use my shower!

I wouldn't agree to this - I don't like the thought of someone who is essentially a stranger, showering in my home.
And I don't think it's necessary either - when I was getting my bathroom refitted, I boiled water in the kettle to wash in the kitchen and used a jug to wash my hair over the bath. Okay, it wasn't nice but I would never have asked my neighbours if I could use their showers - that's just weird!

Me too.

One episode of my kids accidentally opening the bathroom door should fix the issue. I'd try to make sure they didn't, of course.

Gosh. What a weird thing to ask.

I'd be going to the gym or a close friend's house before I asked my neighbour and we're really friendly/supportive of each other.

What's 'batshit' is forcing your opinion as the only correct one.

Same. And just because OP hasn't mentioned an issue like that, doesn't mean there isn't one. So maybe you're being a bit mean to call her nan?!

What a batshit thread. A neighbour using the shower for 15 minutes a day is not in any sense an imposition, or anything to take umbrage at, or anything to get into an anxious tizzy about (unless you're ND). I can't think of many more situations that would require so little of one person to be so helpful to another.

The sprinkling of body horror posts throughout this thread really make it peak MN though. Trotters, verrucas, naked bodies... I have honestly never witnessed such utter revulsion at the human body as I see every day on MN anywhere else.

Also this is so commonplace? Boilers break down all the time. I've been on both sides of this. I was lucky to have friends living very near me both times I was left without hot water, so I didn't need to ask my immediate neighbour (who I didn't know at all). They didn't think twice. I didn't think twice when another neighbour in a different house needed to use my shower. It's called being neighbourly and being part of a community.

I would let her. It would be mean not to.

No, hot water is expensive if you have an electric shower and you have no idea how long she will stay in your shower for each duration.

Why can't she manage using a flannel and some hot water at home? I managed for 3 weeks when I had my new bathroom installed!

Sure. 🫣

She can go to a gym or swimming pool and use their shower. (Plenty of facilities allow you to pay for one-off access) It’s what I did in the past when my shower broke. And I had a very close friend living near by- but I considered that using her’s (in the way your neighbour suggests) would have been an imposition.

If you would prefer her not to shower at yours, that’s what you should tell her. It’s her responsibility to make alternative arrangements. Perhaps it will even motivate her to find a way to have it repaired more rapidly.

Having thought about it more, I would only feel comfortable allowing them to use the main bathroom that the kids use. It has no lock though.

I completely understand why you don't want her to and I'd absolutely hate it but I think in this circumstance I'd say yes. It's awful not having a shower and it sounds like she doesn't have anyone else to ask, plus agree with PPs saying it could make your relationship awkward.

I'm very neighbourly but there are a lot of neighbours I'd feel very odd about being naked in my house! But I can't imagine the circumstances in which they would ask, I do think most people would have a flannel wash or go to a gym if they didn't have friends locally.

I think it's an odd request. Laughing at all the people going 'poor woman' - how do they think many people in the world survive? Or how 'we' lives in times gone by. Giving OP lectures about morals, values, unselfishness etc - pfft.
I'm all for neighbourliness but yeah, odd, intrusive.

Do you have a local plumber who you can recommend who may be able to do it quicker?

I'd let her. It's good to be kind. Just do it on your terms - give a time slot that's convenient for you.

We keep hearing about people feeling lonely, isolated etc. Threads like this explain why

It's not a big ask, will generate friendly rapport and will cost pennies. I'm surprised how many people think OP should say No

But, MN does have a disproportionate number of people who never answer the door......also disproportionate number of people who have no friends....... I think this is connected

Of course yabu and not very nice and certainly not neighbourly

Assuming that everyone lives locally to that type of facility and can easily get there…

This completely sums up how I feel about it. You’re close enough to have one another’s numbers, but neighbourliness doesn’t stop the minute you close your own front door. She wants a bit of assistance for a limited period. I would do it in a heartbeat, this is the minor stuff that makes the world go around.

Surely that's what most of us would do? Changing room showers at the public pool would be my default.

Can she not use the local swimming pool or sports facility?

To me, providing meals and food boxes and help along those lines feels a lot less invasive than using my personal bathroom and bedroom. There are also other options like going to the public leisure centre for a shower.

If my neighbour, who doesn't deserve any favours from me at this stage, knocked and told me she or a child were injured and needed a lift to emergency, I'm right on it. Short on food? Happy to help. Happy to help with most things but would be really uncomfortable letting them use my bathroom.

The other option is to let them use the family bathroom which has no lock and is close to my young children. They could use that but not sure how comfortable they'd be.

No way! This is an odd request. What's wrong with a flannel and a bowl of soapy water? I would say sorry it's not convenient for me. A shower every other day is a lot of water and some expense!