How many people sit between G and her uncle?

We begin by placing F on the table. So we can place D's daughter as follows and hence A takes the other place one spot away from F.

From the clues we know the following genders: A (male), D (male), F (female), G (female) and H (female).

We know that H's husband is not F's neighbour and B is two places to his left and B has no female neighbours. As we try to place H's husband, we see that there are only two possibilities: B is D's daughter or A is H's husband. Let's take the first case:

Case 1: B is D's daughter

Hence, the case would be as shown in the diagram. The remaining two spots would be taken by G and H whom we know to be women.

Hence, D must be a neighbour of B. However, D is sitting to the immediate left of H's mother. This is not possible in the given arrangement. Hence, this case is impossible.

Case 2: A is H's husband

In this case, the family tree would be as shown. As B is two places to the left of A, B is H's mother and E is D's daughter.

D can be placed to the left of B. As there are 5 known women, and B has two male neighbours, C must be a male and must be to the right of B. As G is not a neighbour of E, the arrangement must be as follows:

G's uncle is D. So, 3 people are sitting between them.