Legal Question in Wills and Trusts in Florida

If it was a "joint account with right of survivorship" it belongs to you. If was joint merely for writing checks, no.

It depends on the title to the account as Mr. Slater points out. If survivorship, you are entitled to the funds. If not, it likely is an estate asset. Clarify with the bank.

There are three possible results and two of them aren't good. If the account is titled just as a "joint account" with nothing more, then the account should be part of the estate; if the account reads as David Slater suggests, then, as he correctly states, you're a winner. But if the account was set up as a convenience account (you need to explore the account title and the records at the financial institution), then you lose again. Both Messrs. Slater and Stein have it right and I am not at all surprised.