The term "sticky" really comes down to relevance and value.

Before becoming alarmed at the abandonment rate she needs to accept that many of the visitors now coming may not be qualified prospects. You have approximately 7-8 seconds after time of entry into a site to hold someones attention so plan accordingly. Here is my advice -

1) Get a handle on the terms/sources generating the click throughs and make certain that you are drawing qualified traffic. Unqualified traffic WILL leave quickly, why would they stay?

2) Make certain that the site has a tag line that easily identifies it's purpose/services/products.
i.e., "Professional Carpet Cleaning for Metro Chicago", not vague claims like "Our Services Are #1"

3) Include relevant content that is important to the user. If I've landed on your home page I've probably already decided what I need so don't sell me on "why", sell me on what you can do to resolve my problem. And get to the point quickly! Make the content easy to SCAN, people don't want to read 15 paragraphs of rambling text.

4) Include call-to-actions and conversion elements.

5) Ask prospects that call you to give you comments on site quality, navigation ease, value of content, what they like/did not like about the site, etc. This is high value information.

You need a top to bottom review of the site. What she is seeing is a common problem when a client employs a "web designer" that does not have a clue about Internet marketing. Effective websites are a LOT more than just some photos and words on an html page. Good luck!