According to IMDB, Bitty Schram had only one acting credit after Monk. I wonder if her departure from the series due to a contract dispute left her so embittered that she decided to quit acting.

Why "Monk" fired Bitty Schram (https://web.archive.org/web/20040908010559/http://www.nj.com/entertainment/ledger/index.ssf?/base/columns-0/10941053157610.xml)

Alan Sepinwall reports (https://web.archive.org/web/20040908010559/http://www.tvtattle.com/) that "everything I've heard from sources close to the show since the original ('Monk') story ran suggests that Schram effectively burned her bridges by repeatedly calling in sick to work in an attempt to get a raise. That kind of behavior, if true, does not tend to endear you to your employers." (last item)

Why "Monk" fired Bitty Schram (https://web.archive.org/web/20040908010559/http://www.nj.com/entertainment/ledger/index.ssf?/base/columns-0/10941053157610.xml)

Alan Sepinwall reports (https://web.archive.org/web/20040908010559/http://www.tvtattle.com/) that "everything I've heard from sources close to the show since the original ('Monk') story ran suggests that Schram effectively burned her bridges by repeatedly calling in sick to work in an attempt to get a raise. That kind of behavior, if true, does not tend to endear you to your employers." (last item)
If that is true, it’s a shame. I liked Schram as Sharona. I hope she is doing well.

Why Did Bitty Schram Leave Monk? (https://www.looper.com/924073/why-did-bitty-schram-leave-monk/)

Schram may have left due to a contract issue

At the time of Bitty Schram's departure, a USA Network spokesperson released a statement noting that "Monk" had decided to move in a new creative direction. This change in course would include Schram's exit from the series.

The statement continued, "We thank her for her notable contributions and wish her the very best" (via Today (https://www.today.com/popculture/no-sharona-bitty-schram-leaves-monk-2D80555156)). Schram's management firm, Untitled Entertainment, gave a similar statement, emphasizing that the situation was amicable and that Shcram wished the best for the rest of the cast and crew. While neither of these statements specifically address it, there are reports that the exit was due to a contract dispute, as reported by Entertainment Weekly (https://ew.com/article/2009/03/24/monk-exclusive/).

Luckily, Schram and USA Network were able to reach an agreement for her to return for a single episode of the final season, titled "Mr. Monk and Sharona." In the episode, we learn that Sharona has separated from Trevor for good and is managing a veterans hospital. Further, Sharona is happy to report that her son is all grown up and looking at colleges. She is back in San Francisco to arrange the funeral for an uncle who has just died (which leads to Monk looking into the death when he suspects foul play).

Addressing Schram's return, "Monk" star Tony Shalhoub told Entertainment Weekly, "We couldn't think of a better way to help wrap up the series than with the return of Bitty's character. Bringing some closure to Sharona is long overdue."

Schram has spoken about how happy she was to return

In 2009, the year that "Monk" came to a close, Schram and Shalhoub spoke with MovieWeb (https://movieweb.com/tony-shalhoub-and-bitty-schram-dish-on-monk/) in a joint interview, discussing everything from what it felt like to have the show wrapping up to what it was like to have Schram return for one final episode after such a long hiatus.

When asked if it was easy to revive the chemistry between the two characters, Schram answered, "It was honestly like I never left. I swear, it's exactly what he said. It's a bizarre phenomenon, but it's true." Shalhoub then told an anecdote from their first day working together again, telling MovieWeb that while they were doing their first scene together, the two of them just started laughing because it felt like no time had passed.

It would seem that Schram was ecstatic to get to return to "Monk" for an episode in the final season. She told MovieWeb, "Being back on the show, I was really happy to do it and I thought it ended really, really well. I couldn't, I just thought it ended the way it should have and I was very, very pleased with it and very pleased to be working with everyone again on that show, I really was."

If you're curious about Schram's run on "Monk," the series is available to stream on Amazon Prime Video.

Why Sharona Is Not In Mr. Monk’s Last Case: A Monk Movie (https://screenrant.com/why-sharona-not-monk-last-case-movie/)

Sharona Fleming (Bitty Schram (https://nedhardy.com/2022/03/24/bitty-schram/)), Adrian Monk’s first assistant in the famous procedural show, does not return in Mr. Monk’s Last Case: A Monk Movie (https://screenrant.com/tag/mr-monks-last-case/).