Way to go Frank!
I liked all the low or no cost suggestions, poetry etc. A self made coupon for a night out to include dinner, and a movie or concert or play depending on HER taste is good but don't forget to get her at least a single red rose bud if not more flowers. Women might protest but few really don't want to receive giftw with absoluttely no practical use. I have bougt my wife rifles, a pistol, camping gear and on and on but you got to throw in something with no practical application once in a while. Flowers are good for that.
If I bougt my wife a Gucci anything that cost over $100 I might regret it (she is frugal that way) but if I gave her a weekend in a bed and breakfast place with a view and lots of lacy curtains with the room dressed up like a picture in house beautiful she would swoon. If it were in a quaint looking area and was within walking distance of antique and collectible junk stores she might try to check to see if aliens hawd replaced me with a replicant that she might prefer. First she might worry about my wasteful spending but if I put down a non-refundable deposit so she couldn't get cold feet, she would go and have a good time.
It is a phony deal and not official with any REAL astronomical society in good standing in the scientific community but she might get a kick out of having a star named after her. You get an official manuscript detailing the coordinates of HER star. Guys might think it silly but broa uhh errrahh ladies go for that sort of thing. I've seen the reaction on women, quite positive.... HER STAR!!!!
Best of luck,
Patrick