I think the thing to bear in mind is quality over quantity!
A well trained voice should be able to express three octaves relatively easy, and these three octaves should be accessible in all vocal qualities (with the proviso that belt done low will sound rotten and duck like and speech done high will also sound odd) - your falsetto quality should be accessible everywhere in your range and if you can reach a certain high note in 'falsetto', you ought to be able to sing it in other qualities too.
I never find the chest, head, falsetto model helpful, because I feel it confuses sound and register.
I subscribe to the model that describes the voice as : Low, middle and high registers; and describes sound in terms of the vocal set-up used to make it. Almost all set-ups should be possible in all the parts of the voice (so you ought to be able to sing in falsetto at the bottom of your range and in a very thick sound at the top - it's hard though!).
If you fancy developping range, sirening is a great tool for this and it seems to me that your teacher has some Estill training, right? She'd be able to help you loads with this! Once you've established your range with a good strong tone in an accessible quality (usually a cry quality for Estill purposes) then you can practise using other qualities in different places.
You have a great voice (little aside for others reading this - I've heard Wolfie sing) and with some work, you'll have a nice three octave range with a good tone and a good range of different artistic options.
Allan