AIBU……just not responding to texts.

AIBU? No. Is she rude in not replying to your text ? Yes. I have a daughter in law who never responds to my texts either so we text infrequently. Rise above it - just another thing you have to "let go" it seems. Some people are just ignorant and there's very little you can do to change that!

I think it comes down to good manners. You are letting them have the place free so they should at least text back to say they have arrived safely and all is well.
However, they may be just settling in and intending to reply to you after .
Give them a little time.

Don't understand why some people think it wrong to charge family to stay in privately owned accn! I don't own a property to let but there are family members who were bequeathed a lovely bungalow near the sea, they charge everyone, family or not, to make use of it, not even a discount!! At the end of the day, occupied or unoccupied, there are still expenses to be paid on any property.

"You are adding 2 and 2 and making 56!"

As, Sago, are you.

It was remiss of your SiL not to acknowledge your text, but as they say, no news is good news so presumably she got into your holiday let eventually.
What would definitely "off" is if she did not quickly get in touch to say how charming the place is and how.much she appreciates your generosity.

She’s being ungrateful and rude. Too bad that she has ruined any future chances of ever staying there again.
Why do people have to be like that?

Shes rude

In the ‘old days’ it would have been a phone call and even those who aren’t text savvy must admit that finding a call box was a lot more of a nuisance than a beeping smartphone
And in the OLD old days it would have been an entire letter
Civility takes 30 seconds
Charge her next time!

You sound very needy. Why not give her the benefit of doubt and assume she is busy unpacking and settling in. I'm sure she's already thanked you or will at the end if her stay. Your text did not actually require an answer, you gave her the key code which she needed to enter. Why post on here for all to see, making out you are the good guy but jumping down anyone's throat who disagrees with you!

There’s nothing needy about expecting basic courtesy and good manners.

How rude, made worse by the fact that you could clearly see that she had received and read the msg. It only takes a second to respond with a simple thumbs up or a smiley face to indicate all is well and say thanks.

Totally!!

I personally consider it rude when people don't reply to a message after a reasonable length of time . It's one of my pet hates . At a push a 👍 will suffice lol.

If this was me, I’d think they were rude!

Send another text…..
“Just checking if everything is ok?”

As neither of your texts were answered (2021 and 2023), are you sure you've got her correct mobile number? Just a thought.

Rude and I’ll mannered.

You have been generous and a wouldn't offer again or get her to phone for the key safe details next time!

A thumbs 👍 up at least to let you know all is well.
Most owners of rented holiday type accommodation make contact to ensure person has arrived and found no problems. (I know there is no cost to SiL.)