I for one choose to trust my peers who spent weeks hearing all of this and poring over the details. Could it be biased? Sure, that's possible, juries aren't perfect. I just don't understand the rush to assume a sexist bias based solely on the aggregate sentence lengths.
Any such analysis would have to start with the fact that he was convicted on 12 counts, and she was convicted on 4.
Statistically the gender bias in sentencing is very established / clear cut. There is a lot of academic literature on it.
It seems strange to expect this bias to not have influenced this case too.