Don't worry about the length of your reply. You should see how long winded my posts are. LOL. Anyhow, the more info, the better your responses from people will be.
So, your partner is right. Rubbing the nose in it has nothing whatsoever to offer a dog's education. Has she been scolded for making messes? There should be no scoldings, but rather prevention of accidents. And just taking he pup out often enough.
I like crates because they won't tend to foul their "den." So, when the dog cannot be watched, she can be put in there for that time. I don't like excessive confinement as in people who leave them in there all day long....8 - 10 hours. That's not good. But overnight or short periods during the day is fine IMO. However, you'd need to get her use to one gradually with all positive associations.
The laundry room would save your carpet, but it may not teach her to go outside at those times she is choosing to not go outside. So, you'd always be plagued with this problem.
You could confine her to the laundry room, but get up at night once to take her out on her leash and stay with her while she tries to go. And then praise like mad and give a special treat. Would one time be enough for her, do you think? It's a hassle, but the more successes she has.....the fewer times she goes inside, the better she'll catch onto the idea that it is NOT ok to go inside....ever.
In the laundry room, maybe you could partitian off a very small area, just enough for her to sleep, stand, turn around, stretch out....and no more, maybe room for a bowl of water. (I don't like keeping water from dogs ever, but that's just me. It's a terrible feeling to be thirsty. Some people do remove water at night) You could make it out of something that she can see out of if you think that would ease her into being in a very small place. Just be careful she can't get hurt on any materials if she messes around with stuff.
Anyhow, punishment really doesn't teach anyone anything. If she's been scolded, that can make her nervous and submissive and afraid after she goes...like, "Gee....I go to the bathroom and then I get in trouble." You have to show her somehow that you want her to go outside to pee and only outside. You'll have to do the leg work....taking her out in the rain and preventing indoor accidents, even in the laundry room. When she complies, right after she goes outside, praise like crazy....give her a party, treats, make a big fuss and eventually, she'll get it.
She probably ought to be able to go over night without having to go, if it's not more than about 6 or 7 hours. The sound of the rain may be making her a little nervous. At other times when it rains, you could go out and play and have fun with her...show her that rain isn't going to make her melt. Associate rain with fun and treats and a nice, playful rubbing down with a towel when she comes back inside. Spend some quality time in the rain with her. LOL. Sound fun? LOL. She'll apply that to other areas, I think...as in going outside to go to the bathroom in the rain at night.
I hope some of these ideas are useful. Maybe someone else will have some more for you. Good luck.
Anyhow, 6 months is really very average for housebreaking. Many dogs take longer. So, an occasional accident is bound to happen if you get lax in supervision. That's par for the course. My Dobe wasn't reliable until he was about 9 or 10 months. Other dogs I've had, much earlier than 6 months and some right around 6 months. So, your pup is doing great all in all.
Edited to add: See what I mean about long winded posts? Gosh. I'm so embarrassed!