Certain parent

MOM

She’s often the one who packs your lunch with a little love note inside.

The clue "Certain parent" is a straightforward definition hinting at a specific type of parent. Here, "certain" suggests you’re looking for one particular answer rather than a general term, and "parent" narrows it down to common terms like "mom" or "dad." Since "mom" is the more universally concise and fitting answer, it’s the clear choice—no wordplay or tricks, just a direct match.