Re Tchine height and needing to learn and play GA
I thought she did a great job at GS and 191cm is tall enough to be a successful international GS. Her strength will improve with further training and time and hopefully her skills and movement will too.
For comparison:
Garbin is 184cm
Bueta is 191cm
Koenan is 190cm
Harten is 188cm
Folau is 188cm
I only point this out because all of the above players have been critical players at GS in winning CWG or WC campaigns.