恵那ちゃんだ 電話 そのくらいに しとく
恵那ちゃんだ - it’s Ena (how did the dad know it was Ena at the door?)
電話 - telephone
その - that
くらいに - ???
しとく - to do in advance; to do as a preparation
Sorry, lots of questions here! その has to be followed by a noun, right? So what noun is くらい? Yotsuba’s dad is telling her to do something, put down the phone I’d guess, but where is that in そのくらい? Any help much appreciated!