$P, Q, R, S$ and $T$ are related and belong to the same family. $P$ is the brother of $S, Q$ is the wife of $P$. $R$ and $T$ are the children of the siblings $P$ and $S$ respectively. Which one of the following statement is necessarily FALSE?

1. $S$ is the aunt of $R$
2. $S$ is the aunt of $T$
3. $S$ is the sister-in-law of $Q$
4. $S$ is the brother of $P$