Hello. I understand the underlined sentence, "Heck, I am too." means "I am also too young for all these worries."
Is that right? But in that case, I don't think it makes sense. Because the speaker's mom is old enough for all these worries.
What do you think? Thank you.
from A Bird on Water Street by Elizabeth O. Dulemba----
"Mom, I don't want to move."
"What are you talking about?" she asked. "Oh, did you overhear your dad and me?" She sat on the end of my bed.
"Things are getting better around here," I said. "Nature is coming back, things are growing."
"Honey, your garden might be doing well, but the town is drying up. Your dad needs a job."
"He'll find something," I said. "He has to."
"Oh, Jack, you're too young for all these worries. Heck, I am too."
She ran her hand over the quilte she'd made for me, stopping on the flannel print that had been my baby blanket.
"And you're getting too skinny. Come eat."
"Because the speaker's mom is old enough for all these worries."
Not in her opinion. Your interpretation is correct. The mother is stating that she also is too young for all these worries.
Equally idiomatically, she could have said "So am I" instead of "I am too."