ANSWER:

They can’t sit with the potential suitor as he is non mahram to them.

The father must authorized his brother to be her guardian and sit with the suitor.

The father lives in a different country. But the paternal uncle lives in the same country as his brother’s wife and daughters. Since the father can’t be there, who should be in the marriage meeting when a man comes for his daughter? Is it permissible for the mother and daughter to be there with the potential husband and his mother?