It's just the choice of using 'jutsu' over using 'skill'; that discrepancy aside (which is just a matter of personal choice), the translation is exact. That sentence has a lot of things that don't translate directly into English or would sound really strange if they did. Tsunade says 'jutsu no shugyou kurai nara' (if it's the extent ['extent' as in relating to, not level] of his jutsu training) 'mou asa kara demo hajimerareru' (already from tomorrow even he can begin ['even' relates to 'tomorrow', not 'he']). I think Inane did a pretty good job of wrangling that puppy into English....

Since she uses the phrase 'jutsu no shugyou' [super-literally 'training of jutsu' or 'training relating to jutsu'], it's pretty safe to say she's just talking about jutsu in general...remember, she may not even know that Lee can't use ninjutsu or genjutsu, since he was put out of the game before she came to Konoha.