Known under a number of variants names (mostly based on Ella Fitzgerald & Her Famous? (?:Band|Orchestra)), this formation is pretty much the former Chick Webb Orchestra, without Chick Webb.
It lasted a couple of years under Fitzgerald leadership, before breaking up during the summer of 1941 - though a number of Decca sessions later that year were still issued under that name, with about half the former members (eg: a quintet) - these were Decca 4007, 4073, 4082 and 4291.
Barely looking for "early" Fitzgerald? Or just Fitzgerald in general? Check general Fitzgerald notes for suggestions.