Relying on your kids for emotional support. I feel this happens a lot when parents lack the resources they need. But it's bad because you're throwing adult problems at a child, which can make them feel helpless and not equipped to solve problems later in life. Basically giving them impossible problems for their maturity level like someone here mentioned, really puts your kids in hard mode early on.

It has other effects like the kids think that to survive they need to support their parents emotionally. To adapt to that circumstance involves suppressing their own needs. As adults they may feel like they can only be caregivers, or they may feel resentful when they need to care for others due to the sacrifice it's always involved.