Where Are the Older Heroines?

Where are the older heroines in romance novels?Not there. Not often. Not that I've seen.And by older I only mean, like, getting close to forty. It seems to be okay for romance heroes to be forty or above - though I've noticed the author may let you know only once or twice and then not mention it again - but heroines? Not so much. Fifty and above? Even close to fifty? Where are they? Are