I have a couple of ideas.
The first idea is...make a personalized coupon book of things that you could do for your mum...throughout the month, year or week...or whatever. Make sure to put an expiration date too...and notations like "coupon may not be used in conjunction with any other coupon offers...unless you ask reeeeally nicely...etc." HAHA. It's more fun that way. You could put stuff like "good for one 15 minute massage"; "one free lunch"; "pass to a movie" (you don't have to go out...it can be at home); "one free dessert"; and anything else you can think of. I have tons of ideas but I didn't type it out because I thought you might want to come up with your own. Plus, I'm lazy.
Also, you don't have to that general. For example, if you were just making a coupon book for the week, you could arrange these things according to the days (i.e., "monday massage-15 minutes"; tuesday trip to lunch"; "wednesday wash: laundry on me" (as in you); "thankful thursday: one free dessert"; "fun friday-good for five free lotto tickets"; "saturday steak night" (make her a steak dinner or take her out...whatever); "sunday son-free time with son". i don't know...something like this. i have all sorts of coupon ideas/methods. i type and print it out on card stock paper too!
Second idea is (if you don't want to hassle with the coupons)...get your mom a purse/bag and put a bunch of lottery tickets in there...scratchers and/or numbers (quick picks). It's simple, creative, and exciting.
Btw, to anyone who's reading this...these ideas...especially the coupon book idea...it works for all sorts of occasions (i.e., valentines...lol....you know what things you could put in that coupon book). I haven't been able to try that out yet, but it sounds like fun. Try it.
However, I have made a coupon book for my mum for mother's day. she enjoyed it so much. she would literally use the coupons too, and got quite upset when it would expire. LOL one time she was on her menstrual cycle and was craving some major sweets, so she took out her "mother's day coupon book". it was so cute. anywho, she took out the coupon book and got all upset, and i was like "ma, what's wrong??" then she said "dumit (that's how she says "damnit"), my dessert coupon expired!!! (full on asian accent and everything!)" LOOL i was laughing so hard. it's just one of those moments. but yeah, i got her the dessert anyways and she appreciated it. it was so adorable!