Dependant visa expiration // stay as a tourist

Hello everyone,

I need your advice in two topics regarding my wife's status in the UK.

My wife’s visa (Dependant visa based on my previous SKilled worker visa) is expiring on January 14th, and she’s currently in the UK. We are not thinking at the moment about extending her visa but as she is Polish, theoretically, she could stay in the UK for six months for touristic reasons (no work) even without applying for visa.
So our plan is that she could stay couple of weeks/months in the UK without applying for new visa and then decide if she will stay longer and apply for visa or just go back to Poland. I have two doubts about this case though:

1. Does she need to leave the UK when her visa expires and then re-enter as a tourist, or can she simply stay without any issues?

2. If she re-enters as a tourist and later wants to apply for a Dependant visa based on my Global Talent visa, can she do so while staying in the UK, or does she need to leave the country and apply from abroad?

Thanks in advance for your help!

Once her dependent visa expires, she becomes and overstayer.

1. She would have to leave the UK and reenter. She also risks being refused entry to the uk as a tourist as she is obviously not a tourist.

2. She would have to leave the UK and apply abroad. She cannot switch to another visa category if she is in the uk as a visitor.

Note also that her ILR qualifying residence will be broken if she doesn't renew her dependent visa, if ILR is the aim eventually.

Thank you a lot for your quick response. That's what I thought so she will need to leave UK then. But also it is good to know that actually she also needs to apply for a new visa from Poland. Thank you again!