Schengen Visa Rejected

[Teresa]

I got a friend who applied for schengen visa in French embassy in Singapore but was rejected due to insufficiency of funds. She has about SGD10k in her bank account, fully supported and considered valid. How much is considered sufficient to support the trip? Can you please let us know how to go about this, like appeal or reapplication?

Alternatively, can we apply in another schengen member state?

Thank you very much for you responses!