What is an upper middle class lifestyle

She earns a total of $45M. After taxes she takes home about $30M.

This does not leave her enough money to support property taxes and upkeep on the $25M property. She cannot live off her investments, but has damned herself to continue working and being salary dependent - maybe even paycheck to paycheck - for life.

I think we can all agree that none will weep for her life of toil and sacrifice ;).

The only thing that really works as a definition is a strict math definition. Look at incomes, break them into classes. Anything other than that is just an opinion.

I’ve never seen people agree on what rich/wealth/upper class means though.

Rich is anyone with more than you, poor is anyone with less seems to be the most accepted definition.