I was hoping there was dating info or the item could be dated. That style is within the parameters of Ruth's war years, ca. 1943-6 signatures, so I agree with Steve C. on this one. I don't think I've seen that exact signature before (verbatim), which limits the chances of a swipe and transfer from another source to at least 50/50, so if there's a discernable track and evidence of live ink that rules out transfer or printing, IMO 90/10 good.
It is. There's several experts in the field that don't like any Ruths with that "War of the Worlds" tripod walker type 'R', not to mention Bs and Rs whose starting line more resembles a "V" rather than the upstroke mostly retracing the initial downstroke. But for the ca. WW 2 years, it's normal and quite commonly a sticking point for authenticating material that is not easily dated.