Class 1 diary note: please don't teach borrowing at home

Our younger daughter is in class 1 and has started two-digit subtraction. I showed her the way I learnt it, crossing out and writing a small 1 next to the number. Today there was a note in her diary from the teacher, polite but clear: please don't teach borrowing at home, the class is working with place-value blocks and number lines first. I understand the reason. The problem is that she now does it my way at home because it's faster, and then gets confused in class. Should I stay out of her maths homework completely for a while? I don't remember this coming up with our elder one at all.