Great podcast! To the woman (or anyone else out there) considering Haleakala, do it! I did it in October. I had been away from any serious riding for years, and had virtually no base fitness.
I started out with some group rides over the summer, and bought a smart trainer and signed up for TR in August. That gave me just enough time to complete a Sweet Spot LV and a Sustained Power MV with some hard group rides in the mix. FTP went from 164 on my first ramp test ever to 204 after Hawaii. My weight went from about 150 to 143. (3.1w/kg).
West Maul Cycles blog posted above is a must read. We also rented our bikes from them and it was good experience, and the bike (Roubaix expert Di2) was excellent.
Nate mentioned paying to get into the park - don’t forget it’s credit card only these days! We also had to hitch hike back down. If the cloud sticks around it is a cold and wet descent.
As everyone says, the ride is tough, but doable. Meaning it never really gets that steep except for 2 sections, with one coming right at the end. But if you’re feeling any doubt by then, just pull into the lower parking lot, take a little break, then hit that last 10% 1/2 mile with everything you have left. That’s what I did, but in hindsight I probably didn’t need to. Could have jumped several Strava positions without the break 
One thing I would do differently is get a couple more long rides in. I didn’t do anything much more than 3 hours in training and the ride took me about 4:20 (moving time). My limiting factor became leg soreness and general discomfort on the saddle. Good Luck!