Trouble extending a component

I'm trying to extend a component, but my new marquee.html updates aren't rendering on the page. The dialog updates are okay. Here's what I have:

Parent component

marquee
> _cq_dialog
> clientlibs
_cq_editConfig.xml
.content.xml
marquee.html

Child component

marquee2
> _cq_dialog (All these updates are working.)
.content.xml 
marquee.html (None of these updates are working.)

Shouldn't any changes in the child component's marquee.html file override the parent file? I've been researching to see if I missed a step and everything seems to be in order, but apparently I'm missing something. Thanks for any help.