I took up flyfishing 8 years ago, I am self taught and get by, known to catch the odd fish here and there.
A couple of weeks ago I took my girlfriend fishing, it was her first time flyfishing so I thought with her being a newbie, it would be a good idea for her to experience some success. We went to a cutty stream out west, I took her aside and spent 30 mins showing her the basics of casting and reading the water, after a bit of practice she could shoot the line 15 - 20 ft, enough for this stream. I brought a rod (my back up) along but did not fish very much, it was her outing. By the end of the day she had caught 16 fish, varying in size, she (we) had a blast, she felt the line tighten time and time again, needless to say the girl is hooked. I loved the outing, watching the look in her face as she stood on the edge of a pool waiting for a fish to rise to her stimulator was priceless, a look which later on in the day became known as the “Hannibal Lector” look, too funny.
Anyways, now I have a problem, a BIG problem, she really liked my precious expensive rod, my Z-Axis with my Orvis Battenkill LA. We are now pricing out waders and wading boots, rods and reels, and everything else required to look the part.
So, I might have just kissed my Axis goodbye (I do have other rods), unless of course one day she is not fishing and might allow me to use it, on the other hand, she might just understand the need to get new expensive gear.
I light of these new developments, I feel compelled to make some decisions regarding spending at our household, heck, one of these days I might just have to remortgage the house to finance the addiction.
Saltamontes
You LUCKY dog !!
If you lead with your chin, expect to get hit on the chin. 
My little pumpkin patch started out like that, Had a great day and caught tons of fish, and now you just can’t stop her. Luckily she started on an inexpensive rig and has stuck with it. I started her with the $79.00 Wal-mart SA combo which is really a very good outfit for the fishing we do.
I do not intend to tell her that their are more expensive rigs even for sale. That would just be dumb.:lol:
I saw that one coming as well and started my wife (my girlfriend at that time) on the TFO Pro series. She fell just as in love as she would have otherwise and so far isn’t eyeing my Scott or my HM3 ;). The important thing is that we fish together> If it would have taken a $700 rod to accomplish that it still would have been worth every last penny.
Well, lets see now. You now have a girl that loves to fly fish AND you MUST Give her your rod and reel resulting in the need to purchase a new rod and reel. You call that a problem? The only problem that you have here, from my point of view, is that she is now going to proceed to out fish you! Good for her…and you. You the man!
Thre’s no solution for that…I know it, I had and I have the same problem. Sorry.
Rocketfish
Let’s see, your girlfriend likes to fish. She’ll go fishing with you any time you want. I’m sure she looks better and smells better than most of the guys I fish with. She likes your expensive rod.
Now you have to buy a new rod for yourself.
Remind me again what’s the down side? 
Jeff
Give her the rod. Get yourself a new set-up & everyone’s happy.
:DThis is Probaly the Best “Problem” You will ever have!
Congradulations
If only I was as fortunate as you. My wife loves fish, but is not one for fishing. 
Seems to me the Sage is a small sacrifice for gaining your better-half as a fishing partner.
My wife expressed an interest in learning to fly fish about 10 years ago. She now has 6 rod/reel line combos including bamboo and two handed rods. She also expressed an interest in tying flies about 4 years ago. Now she has three vises and four cabinets full of tying supplies.
You’ll find your fishing budget jumps considereably when you have to have two of everything. The great thing is you don’t have to fib about the price of the new rod or reel as she’s probably had her eye on the same piece of equipment.
Sounds like you found a keeper.
I read your whole post twice 'cause I thought that you might have a problem ( I look for folkes with worse luck than mine so that i can feel good about Me) and then re-read it.
I fail to see any form of a problem here . Come on, do the right thing, Man up and give the girl the gear. If she really wants it she’ll get it any way , so if you hand it over before she asks it looks like its all your idea. You get the credit and she’s all flush with “good will”. Talk to some of your “older” married buddies about “Good will” and the benifits thereof.
Another thought.
I hear that the new “Helios” are too cool.(flygoddess can tell you)
Mention it to your girl around Christmas time(subliminal message{good will})
Remember these two critical words:
Good Will.
Cheers,
Perch