Since this word is made up of a single kanji, it uses the kun'yomi reading. You have to remember the かあ portion. Here's a mnemonic to help you to remember it:
What does your super nice mother do for you (this is why you're so polite to her!)? She drives you all around in her car (かあ) taking you wherever you need to go... soccer, kendo, whatever. What a nice mother you have!
I'm your mother, so I can pay for your flight for you.
My mom’s nose hair is long.