Glider rating

[boofhead]

Question for the US system:
My daughter is doing both glider and powered training and is about ready for her private certificate checkride in both (she is 17). As usual she is dithering about with her groundschool.
She has (or will have) 40 hours powered and could do her powered checkride first, then get her glider checkride for a private glider rating.
If she does the powered written, does she need to do another full glider written? She has checkitis and I am sure she will not pass first time, and the cost has recently gone up to $120 for the written, so if she does both that is $240 and if she fails one or both the cost would be more than she has available.
I have always assumed that adding on a glider rating to a normal Private certificate would require the experience and a checkride, no written, but I could be wrong. I cannot find anything about this in the regs.

[galaxy flyer]

boofhead

This from the Soaring Society of America:

Additional Pilot Rating
Holders of a valid FAA Power plane license with 40 hours as pilot-in-command need a minimum of 10 solo flights to qualify to take the glider flight test. No written exam is required to add a glider rating to a power license. In all cases, refer to the Federal Aviation Regulations for details on pilot licensing.

Link is here (http://www.ssa.org/sport/gliderpilot.asp)

FAR 61.109 (f) is the applicable rule. If you can find the Practical Test Standards guide on-line, I'm sure it has the prerequisites for the test.

GF