Because freely downloadable fonts, and Edwardian Script is no exception, quite often are available as a single font family member -- regular. You will need a bold family member to get bold results. And these free fonts often are not up to the same quality as surrounding fonts included with OS X and installed applications.
If you want a professionally designed font in bold weight, then visit Linotype and purchase ITC Edwardian Script for $58 and have both type faces.
Font- edwardian script...i really need bold and it doesn't offer it?? why??
Some apps, like MS Word, let you create fake bold from a regular font, and perhaps that is the feature you are looking for. Pages aims for a higher typgraphical standard and will only do bold and italic when actual bold and italic fonts are present.
You can download bold here for $29.