Technically speaking you do not even need to be a priest to be a cardinal. The most notorious instance was Cesare Borgia, whose father was Pope.
But the days of the Borgias are past. They were a scandal to the Church. This particular appointment was legal, but clearly not in the Church’s interest.
In other words, it would be legally possible, I suppose, to name a woman a Cardinal, although she could not be made even a Deacon. But I think it would be exceedingly unwise. The historical precedents are not really favorable.
As others have already pointed out, this sounds like another media speculation or smear.
Yeah; we get NEW scandals these days!
OTOH; guess who selects each pope...
A bunch of CARDINALS!!!