How to make the Pages display in sidebar, show only the Parent Main Pages

Dear Flynn and All, a month ago I was absolutely ignorant of web building. But I have created a blog which is working - an achievement made easy because of the amazing Atahualpa, and the Q&A forums. Thank you! But there is one thing I cannot figure out.
I am using the Pages widget to permanently store articles - and there will many of these. At the moment, both Parent and child pages are displayed in the LH sidebar. If I store for example 100 articles (100 pages), the list will extend way down the Home Page of my blog. To overcome this, I want only the Parent Pages (3 or 4 of these) to display, and the child pages to display in a drop-down menu, on hover. Can this be done.
Thank you anyone for help.
my blog is www.brisbanegoodwill.com