jj1968 is being economical with the actualité again.
The linked spreadsheet does appear to be what the programme is based on, and is split into crime survey, police, and other data.
That document does indeed group together "rape or assault by penetration" in all the crime survey data in tables 1-31.
The crime survey only record "sexes" of those performing the abuse in one table - table 13. There I see a "3.8%" under "sex of perpetrator(s) = female" for "any sexual abuse experienced before the age of 16", but that's not quite the same thing as "3.8% of perpetrators are female" stated in the OP. The same column has "male = 91.7%" and "both male and female = 4.5%". And the data is from the ONS crime survey, not the police.
(It's worth noting that 78% of the victims responding to the survey are women while we're here...)
Like other crime survey tables, that table groups together "rape or assault by penetration". So we see "rape or assault by penetration (including attempts)" = 565, with 95.7% male, 1.7% female, 2.6% both.
However jj1968's statement "The category Rape refers to rape or assault by penetration" is not supported in any way by the screenshot or anything I can find in the document. The survey section always uses "rape or assault by penetration" and never shortens that combo to just "rape".
The police stats in 32-37 do break out just "Rape", and a bit of research suggests they really do mean "rape" in the legal definition "with a penis". They're showing offense codes like 19C ("rape of a female aged 16 or over") and 20A ("sexual assault on a female aged 13 and over").
This document confirms that 19C is used for penises and 20A otherwise in these examples:
Where woman believes that they have been penetrated but is unsure with what, there is a presumption that it will be with a penis unless there is clear evidence that this is not the case.
4: A woman makes a complaint that she has been date raped. She believes that her vagina has been penetrated but she can not provide any further details surrounding the assault. / One crime (class 19C). / Following investigation into the offence it is established that a physical object was used and there was no penile penetration. / The FCR can reclassify the recorded rape to one crime (class 20A) (assault by penetration).
5: A woman is accosted at a party and pushed onto a bed by a suspect. Her trousers are removed and she feels her anus being penetrated. She pushes the suspect off her and discovers that the suspect is a female. / One crime (class 20A) (assault by penetration).
The spreadsheet linked by jj1968 does not have any police data on sex, but we can safely conclude that the 19,481 rapes (of 15,779 females and 3,702 males) were by men, based on the codes.
The "382 rapes by women" number elsewhere in this thread does not come from that spreadsheet, but I gather from police reports.
Until we see otherwise it seems reasonable to assume that the police mean "penis" whenever they say "rape" in their stats. Assault by penetration comes under a different general "sexual assault" code for them, even if judges' sentencing guidelines treat them the same. It's not clear that the police could easily separate out "assault by penetration" from other "sexual assault" for stats even if they wanted to if they're coded the same.
I was prepared to give jj1968 the benefit of the doubt, so dug into it, but I am disappointed again.