The time and money were the ongoing challenges.

Her flower shop provided income, but it was not a source of substantial capital.

Her inventions were developed in parallel with her regular working life, in the margins of time and the edges of a budget that had to cover ordinary living expenses before it could cover patent fees.

This is the practical reality of independent invention for most of history: it happens alongside regular work, not instead of it.

Thomas Edison had a laboratory funded by investors.