Jenny is a fast and talented rider and I hope she goes well.
However, in general, I feel that most newcomers to the TT would be well advised to try the Manx first. I know there have been exceptional N/C like Martin, Plater, Robinson etc who go straight to the TT and deservedly so but how many others go straight to TT yet wouldn't have even won the Manx N/C race?
I think its an image thing. Every year the TT is boasting its entry of new names but do they ever recommend a Manx first to anyone? In the meantime the Manx N/C is lacking numbers.
Having said that, if you take the top 6 riders at the Manx anyway, they are good enough for TT. Whilst the bottom 10 TT riders should really be at the Manx.
I recall a couple of years ago, a quick club rider, who rubbished the Manx quite openly in the paddocks. Then he went to TT as a N/C and only just qualified, finishing at the bottom of every time sheet and wouldn't have been any better than midfield had he tried the Manx first.