you could always just make her somthing it would be more personal and it would save you $15.
I suggest you to give her a portrait or cartoon. She will be happy to get such a gift) It is unique and funny. So, if you need here's cool website I used:
just give her the love and compation to her j. thats what i did last year.
Look around on Instructables. There are some great projects for under 15 dollars.
Mom's go gaga over any kind of birthday card, try using your non-writing hand, it will look like when you were in kindergarten, she will think it's too cute, (Beware:good-ole mom may be inspired to break out the old embarassing baby pictures!!)
Chicks always dig chocolate too!! (works for girlfriends or wives too!)
Look through Instructables for a project she would like and make it. It is the thought that counts!
Make some candles!
You Should know what sort of things your mom likes, if not, then take notice of her decorations around her house, or her hobbies, or what just what you think to be useful
$15 Starbucks Giftcard?
Sponser a puppy, or a zebra or something for her, one of those "Sponser a ........." programs
Last year, I made a thank you card/coupon. Take a pic of something laying down that spells out "thank you" then put it on the computer in paint and put "expires: NEVER" in the corner.
When you give it to her explain that whenever she's feeling useless to show you the card and you'll thank her for something. It never expires because you will never run out of things to thank her for.
My mom got all melty and hugged me :) you should try it next time.
books usually work well or flowers. if your handy with a soldering iron why not look for an LED flower bouquet or something.
I know it is a little late but I got my mom a gift card to a smoothie place you could get her a gift card
you should give her $15 jkjk
could you at least tell what sort of things your mom is into so by that people here could give a better deduction
And besides if you don't know and ask it could show/hint that you are putting a lot of thought into this *shrugs*
A subscription to Instructables.
No gift is more useful.
Make her a powerpoint for free.
Take her out for ice cream.
Give her a coupon book you made entitling her to some hugs and "I love you's." Include coupons that say you will vacuum the house, load the dishwasher, cook some meals, listen without backtalk, compliment her, etc.
Perhaps a lovely breakfast in bed, with good coffee and a couple of chocolate danish pastries-and a single pretty flower from the garden in a small vase, (or put it in a teacup, taking most of the stem off).
And simply write a letter to your mother telling her how much she means to you; put in an envelope; and put that on the tray.
Find out what she would like then engage it. :P