Awwww, how sweet!

Sorry you had to burn your house down, but it was for the best.

spiders are good luck

Did you have something covering that part of your window? It takes more than 3 days for spider eggs to hatch (generally 2-4 weeks), so you would've had to have not seen them for a while. Black widows and brown widows are both pretty shy spiders that like to live in dark corners and crevices, not bright open windows, so it could have been a false widow (they imitate a widow's appearance like a hover fly imitates bees).

Ah, the miracle of life.