Let $S$ be a set of cardinality $\aleph_1$. Consider the directed family $\mathcal{C}$ (here directed means directed with respect to the inclusion) of all countably infinite subsets of $S$. Suppose that
$$\mathcal{C} = \bigcup_{n=1}^\infty \mathcal{C}_n$$
for some families $\mathcal{C}_n$. Does it follow that for some $n_0$ the family $\mathcal{C}_{n_0}$ contains an uncountable, directed subfamily?
Of course, at least one $\mathcal{C}_n$ is uncountable, so let us take this one. Must it contain an uncountable directed subfamily?
Yes. Letting $S = \omega_1$, one of the $C_n$'s must contain uncountably many ordinals and hence an uncountable linearly ordered subfamily.
Also not every uncountable family contains one. For example, an almost disjoint family.