I think Juhi and Janhvi are too similar for twins.
Some middle names:
Susanna/Susannah
LouisaIsabel/Isobel
CorinnaAnnabelClementineLauraAliceSophia
As both names are one syllable long,
Rose Anne feels abrupt. What do you think of
Rosalind and
Rosamund?
masculine list:
https://www.behindthename.com/pnl/191050/124079feminine list:
https://www.behindthename.com/pnl/191050/124080