Originally Posted by
dedhed
What is her "dated road bike"
Dated road bike bike can mean different things to different people. Anything from a 80's lugged steel to 2015 carbon
Originally Posted by
Hondo6
Current RD will not work with ST-R7000s. Shimano changed the RD pull ratio with 11-speed road - and with 10-speed mountain, FWIW (to something else different from either 10- or 11-speed road).
Tiagra 4700 and one or two other newer gravel 10-speed groups that post-date Shimano's intro of 11-speed road also use the new pull road ratio. 10-speed 105 and Ultegra did NOT use the new 11-speed road pull ratio.
If the OP's GF wants to stay with a front triple, that could be an issue too. Shimano doesn't seem to offer one with R7000 or R8000 (though both groupsets are available with either braze-on or clamp mounted double FDs). And I understand the FD pull ratio also changed with 11-speed road, so a new FD will also likely be required to go R7000.
From the question, was taking it that Ryan meant using the current wheels (9 speed) with a new to be purchased 11 speed R7000 RD/Groupset, in this case, the 11-34 cassette should (according to the Shimano specs) fit on an older freehub.
Thinking this is on the basis that the freehub was 9 speed road, as with many questions on BF, there is a lot of guess work with the limited info given even in this case were is was pretty detailed