Should I give her an inexpensive gift if she won't appreciate it?

Unfortunately, your daughter in law sounds a bit on the snooty side. No need to waste your money on something you know she will not use or appreciate. I would just buy her a nice box of Godiva chocolates with the $25.00. That is a bit of a luxury item most anyone would enjoy. If she does not have the manners to thank you graciously, do not buy her any more gifts, period.

Maybe you should ask your son on this one. I'd say that you should give her a $25 gift certificate to one of her favorite stores or get her something cheap but luxurious. Some nice chocolates (if she likes chocolate) can be affordable but a great treat. The same goes for a bath basket. It can be relatively cheap, but seem luxurious. Get some soaps or lotions in a scent that she likes, and toss in a little manicure kit or one of those nubby massage thingies.

In short, rather than focusing on something she can wear, why not try to focus on something she can consume and enjoy? I think that something yummy that she wouldn't normally treat herself to could be welcome. Especially during the holidays, if she likes to entertain, having something to share (or hoard) is a great thing to have. The same goes for other ways to pamper herself... a hot bubble bath is a great way to unwind after a long day.

If she really only wants things that she can use to show off wealth (pft), try a designer outlet or consignment shop or go with a gift certificate somewhere.

The whole point of a gift is to try to please the other person with something you think they'd like (within reason).

Don't think clothes -- look around for something else entirely. Music or a movie she might like that she doesn't have. A book.

Get her a food basket-type thing.

Or something practical, like for the kitchen (assuming she cooks).

If she's rude enough to snub your attempt to please her, don't worry about it; she's not worth it.

Gift cards have no thought to them, and, in the case of giving to people who care ONLY about the monetary worth, unwisely tell them exactly what you spent. Don't do it. If she's well off, she can buy things for herself.

Aim to get her something she didn't know she wanted until you gave it to her.

I'd go for the gift card, my friend is like that, and it's annoying...her own mother gave her a really nice gift last year, and she said.."what am I going to do with this?" and left it at her house..I would have been so insulted...

I think a gift card is fine. She can use it towards something she wants. If you want, maybe you can supplement it with some homemade cookies or candy. It wouldn't cost a lot, but your efforts are priceless and should be appreciated.