I feed babies once a week, sometimes more if they seem to need it, and more if all I have on hand are relatively small prey items.
My adults eat every 10 to 14 days, sometimes more often if the prey items are small, definitely on the further end if the prey items are large. Usually it's every 10 days, and my adult snakes are fed medium rats at the largest. Lately it's been easier to get large rats, so I offer those every 14 days instead.
Babies are offered something every week, though.
Some other species of snakes can get quite fat even as babies, to be fair. My first experience keeping a kingsnake right after highschool was to inadvertently make it the most obese kingsnake I had or have ever seen since. I fed it whenever it'd come out and look hungry - so from the time it was a hatchling until I realized what I'd done, I was feeding it every 2 to 3 days, except for a 2 week period when it would shed. This snake had ROLLS it was so fat.
In the end I had to cut it back significantly on food and take it out daily for exercise...and it was still the fattest kingsnake I'd ever seen. Sold it a few years ago to someone who loved its fatness, not sure where it is now but I hope it is happily living out its chubby existence.
-Jen