By the time I last August, she’d had it with my “helping.” We stood in the tiny space cluttered with labeled boxes, bedding, an ottoman and a totally impractical but everyone-has-one headboard. “Let me hang up your pictures,” I said.

“No, I’m good,” she protested. When I reached for the nails, she pushed back harder. “You don’t get it.

I don’t want your help.” I chalked up her reaction to nerves — hers mine. We look alike, talk alike and think alike.

This may be our superpower, but it is also our kryptonite. Miscommunication defines a lot of our back and forth, and passive-aggressive behavior (hers and mine) runs amuck. A slammed car door — or, this time, the hammer tossed back into a box — tells me all I need to know.

In hindsight, Emily’s frustration was justified. For over a decade, I’d made an occupation out of helping her. Guilt and desperation can make a mother “do too much.

” (Her words, not mine.) Emily had when she was 4. Her odds of survival were 50/50.

We spent more than 300 nights in Boston Children’s Hospital staring at the infamous Citgo sign and trudging through a protocol of care that threatened to kill her before the cancer did. We were lucky. She lived, but a lot of kids like her die.

The treatment left her legally deaf and damaged her endocrine system, kidneys, height and fertility. Still, the only thing she hated more than hair that refused to grow back was the way I showed up to fix all of her problems. For the next .