Rekmeyata, you're talking to a woman, not a man. And she has a fair bit of experience at working on her endurance and average speed.

Goldfinch, 13.5 mph isn't that slow as an average. When I'm out doing a training ride at endurance pace I'll probably average 16-17, but I train and race, I'm not a recreational cyclist and I've been doing a lot of miles for quite a while. Most recreational cyclists would think a 13.5 average was pretty decent.

I like your strategy. Get decent rest, eat plenty of protein, try the back-to-back rides this week, see how you feel. Do the ride if it feels like a challenge, don't do it if it feels overwhelming.