Child Theme Error

Hi there,

I am trying to make a child theme from Pinboard, so I can modify the content. Unfortunately, when I create the child theme I get this error:
“Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 46 bytes) in /home/content/83/11264883/html/wp-includes/post.php on line 654”

The only thing I have in the child theme is a starter style.css file – no modified PHP files or anything. What am I doing wrong?

Thanks,
Liz