Women's Water-Resistant Packable jacket for day bag?

There should be some good ideas here - https://community.ricksteves.com/travel-forum/scotland/raincoat-2288c9a2-a95f-4edd-8018-159a3a0297a1.

But since you said mid thigh, and you'd like something that will keep you dry, I'm afraid that's unlikely to be as lightweight as you might like. I own this one, keeps me dry on wet Swedish bike rides. https://www.eddiebauer.com/p/20612683/womens-girl-on-the-go%26reg%3B-waterproof-trench-coat

I use the LL Bean "Trail Model" rain jacket, but they also have a longer midthigh length. It's doesn't provide any warmth, but it's been very effective in heavy, blowing rain. I do always like a long sleeved layer underneath because the interior can seem a bit cold next to the skin. The first time I wore it in short sleeves I was convinced that the rain had soaked through, but I finally realized that I wasn't wet...just cold next to the inner waterproof layer. It's very light weight; I can roll the jacket up and put it in my purse.
Good luck with your hunt for the perfect jacket!

I took the Lands End Waterproof Hooded Packable Rain Jacket to Belgium and the Netherlands last year. It's mid thigh and packs up very small. It actually can pack itself into a pouch. It had an elastic band at the wrist rather than an adjustable sleeve, which I didn't love, but it worked out great. We were lucky to have great weather, so I didn't need it a lot, but didn't feel burdened by keeping it in my daypack. And it was comfortable enough as an extra layer when needed.

I have this unlined jacket from Eddie Bauer. I'm 5'2 and the petite size hits me mid thigh. It packs in its own pocket and weighs just over 11oz. I've stayed dry in downpours.

Edited to add this jacket is waterproof, not water resistant.

I’ll throw in another vote for the LL Bean Trail Model. I’ve been caught in some downpours with it and stayed dry. I have the short jacket and would love the longer version. LL Bean never seems to have sales, but if you aren’t too picky about colors, they often give 50% off on discontinued colors.

I have a very nice, waterproof rain jacket from Eddie Bauer (Women's Rainfoil Utility Jacket, which I don't think they sell any longer) that I take on trips. It is large enough that a warmer jacket can be worn underneath. But just this week, I purchased a Columbia Arcadia II Lightweight Jacket that is much more packable and that I will bring for warmer weather. I tested the claim of it being waterproof by spraying it with my kitchen faucet sprayer at full power a few inches away from the fabric and it kept the inside of the jacket dry. Of course, eventually any "waterproof" fabric will be saturated but I think that this jacket will be just fine for unexpected showers and it is lightweight enough to just throw into a day pack. Unfortunately, it is shorter than you want but it can fold up into one of the pockets. I found it on sale at Kohl's for $57 and with a percentage off coupon I had, was able to get it for $47.

Just adding, don't buy anything for full price at Eddie Bauer. They have sales throughout the year offering 40-60% off.

There is a huge difference between "water resistant" and "waterproof." If you are going to buy a new jacket, why not buy one that really does the job? Columbia Sportswear has good quality waterproof jackets at a reasonable price.

Rei Coop and Patagonia also have women’s mid thigh. The only problem is having good waterproofing usually means at least 2.5 layers and that means they’re not going to fold up “very small.” Even ll Bean states the one recommended above as 11 by 7 when folded into pocket pouch but maybe that is small enough for you.

If you have outlet stores nearby - you may get lucky on a Columbia packable raincoat on clearance. I am a female. But, I found a suitable men’s coat on clearance for about $30 - $40. Sierra Trading.com may have something. Do you want a city-looking type coat or is an “outdoor” coat suitable for you? LLBean may have something.

I own the REI Rainier jacket and love it. It’s very easy to roll/scrunch to place in a backpack or mid-size day bag.