Replacing Blogs List in Backend

I'm attempting to replace the backend blog list for the purposes of including a method to hide blogs that users do not have access to. I know that when I lock down a blog, I essentially limit the users ability to manipulate the blog, but I don't want the blog to show in the list at all. So I made a custom widget that I want to replace it with but as soon as I remove the existing widget and place in mine, I start getting a javascript error. 

0x800a01b6 - Microsoft JScript runtime error: Object doesn't support this property or method

  if (jQuery(".sfSiteSelectorMenuWrp").length > 0)

 I've added in jquery 2 ways (sf include way and manual reference) and also added in a div with the class name from the if statement. Still getting the method not existing .length. 

Hello Richard,

Could you please open a support ticket and provide us more information on the widget, the widget template and any script you are using? We will need backend credentials to an environment where we can reproduce the issue and debug it.

Regards,
Nikola Zagorchev
Telerik