70sSanO

I agree with the above. Keep in mind that capacity only comes into play when running small-small, or close to it in cases of extreme disregard; i.e. running a capacity of 40 with a 30 rated RD might impact the first few cogs in the small chainring.

The max cog, in your case 30t can generally be exceeded. The amount over usually depends on your derailleur hanger. This does bring the Wolftooth RoadLink into play. It lets you exceed the max cog by a lot, but doesn’t impact capacity, which means your wife may have to be disciplined enough not to run the 11, 12, 13, or so when in the 36t chainring.

And as stated above, you can swap out the 36t for a 34t. Try it with the 52t. If it were me, I’d swap out the 52t for a 46t and run the existing 36t to see how she likes it with an 11-36 cassette. Everyone will say it won’t be matched, but for someone who doesn’t race, even pretend against unknown people ahead of them, it will work.

You may still be destined for a crank change with a 30t inner chainring, but maybe this will hold off replacing the crank and only dealing with a cassette change, chain, (if you run a RoadLink), and maybe an outer chainring.

John