Hi Nestor!
Thank you for bringing your question to the Disney Parks Moms Panel. This is a tricky question because a lot of it is your wife's personal preference, but I hope some of my pointers can help sort out what work's best for y'all!
A majority of folks in the running community would say to make the run early in your trip. This way she gets the run done with early and has the rest of the week to relax. I would not recommend coming in the day before though, but probably two days before. I have flown in the day before a race before, had my flight terribly delayed and barely made packet pick up because the runDisney Health & Fitness Expo does close the earliest of any day on the Saturday of a race weekend. To accomplish this you'd want to fly in on the Friday.
Personally, when we travel for
Walt Disney World Marathon Weekend I will be arriving on the Wednesday because I'm participating in the Dopey Challenge. I will run Thursday, Friday, Saturday and leave Sunday after the marathon. While traditionally I don't leave the day of the race, I did this for Tinker Bell Half Marathon and actually felt much less sore than I have the days when I've ran then gone into the parks all day. This could be attributed to better training, etc., but from my personal experience this worked great!
If you plan on doing super long days in the park during your 7 day stay, I would not recommend making the run later in your trip because your wife will be exhausted. In a case "do as I say, not as I do" I would arrive on the Friday before the marathon, take it easy Saturday, have her run on Sunday, then you have 4 more days remaining to go all out in the parks!
Please let me know if you have any other questions!
-Lindsey ºOº