Hi Bradley thanks for posting in the Community! My apologies for the confusion. When adding more attributes to a parent card the shape doesn't automatically adjust the position of the child card. If you are adding attributes to the parent after having nested the child you would have to move the child card down to the space at the bottom.
We're always looking for ways to improve Lucidchart and your feedback is the best way for us to do that. If you'd like the adjustment to be automatic would you mind adding that idea to our Product Feedback section? Ideas submitted are passed on to the product development team for their consideration.
Thanks for your request and I apologize for any inconvenience this causes you.