。
Mother told me to come home early, but I ended up being late.
Literal
Mother [subject-が] early come-home [so that-ように] said [but-が] became-late-(regret).
~ように言う is the indirect-command pattern: literally 'said so that (one would X),' it encodes 'told someone to do X' without using a direct imperative. The quotative-free alternative to と言う for commands. The second clause pairs 遅くなる ('become late') with ~てしまう ('regret/end up'), conveying that the lateness was unintended and unfortunate.