If you don't trust the forbes number of $12M that was based directly on her financial disclosure for 2019 and her other publicly known assets, you could look at her actual financial disclosure for 2022.
efdsearch.senate.gov
Note it doesn't need to list all assets (like sector stocks or mutual funds, I.E. Vanguard S&P 500), especially not those in cash, but it is supposed to list income(s).
Now in addition to several million in listed assets of particular note are the multiple entries of bank account interest earned between $100k-$250k on savings accounts. Not CDs, not Bonds, SAVINGS ACCOUNTS.
One with First National of Omaha, another with Capital One.
FNBO's and Capital one both currently have an APY of 3.4% on their highest yield savings accounts (would have been less in 2022), so to earn the minimum of $100k you need right around $3m in cash.
So that's a minimum of $6m in cash sitting in savings accounts (potentially up to $15m). Several million in reported stock holdings for individual companies. Then there's the cambridge home valued around $4-5M in 2022, a condo in DC worth $800k (in 2019, maybe $1.5m now?).
Do you know anyone that parks that much cash without also having long term investments?