When you consider that Dora The Explorer's parents are archaeologists, Peg's grandparents being in love with the sixties, both the numbers and the decade, is not too surprising and really, really cool.
People in the Arab world our responsible for making considerable contributions to both operational math and geometry, so that does provide something of a basis for an episode on Eid-Al-Adha, and since Albert Einstein was a well-known genius who made numerous contributions to the field of mathematics, the same can be said for Hanukkah.
While the opening theme song speaks to Peg and Cat's friendship, they've also been shown to have a sizable circle of friends, so it may very well also serve as an example of Lucky Seven, in addition to making a connection to whatever role the number seven may itself play in the show.
