Welcome to TE!

Provided they have the same level of componentry (Sora? Tiagra?) The difference between the two is a matter of gearing. The Compact has a compact double crankset, and the Triple has...well, a triple crankset. Two chainrings vs. three. This also means that there will be some differences in the cassettes (the gears in the back)--you lose the small chainring with the compact double, so there are usually more easy gears in back to make up for it. Which one is better largely depends on your level of fitness, and how hilly your area. Shifting, though is usually nicer on compact doubles than on triples.

I have an Avail 3, though it's a few years old and the componentry isn't exactly comparable. In similar measured sizes the top tubes are weirdly long. So you'll probably have to go a size smaller. (Specialized fits me better.)
Do you need a women-specific bike? If you have long legs relative to your torso, you might.
Other things to check out: Cannondale Synapse, Jamis Satellite, Trek Lexa. Test-ride everything and get what feels and fits best within your budget. Happy shopping!