Is she correct in thinking that large capacity magazines are in "common usage" and therefore these bans are unconstitutional?
"Large" is not defined but magazines in excess of seven rounds are certainly in common usage. They are the norm rather than the exception.
"Common usage" and "Sensitive places" are two terms in Heller that are critical areas for establishing jurisprudence in favor of RKBA.
Regarding the question above, she is correct in her analysis from an intellectual perspective, but jurisprudentially it has not been established.