Even though you may not cherish the idea of giving a public speech when you are the maid of honor at your sisters wedding you are obliged to provide some sort of speech in recognition of the day. Usually the maid of honor statements are generally told right after the best man statements have taken place.
As with any speech you should start off by introducing yourself and explaining what your relationship is to the bride. Begin by offer the bride and groom a congratulatory statement and move on to the reminder of your speech. Of particular interest in your sister getting married is that regardless of whether you were close or not the two of you will always share the bond of childhood. You were there with each other as the years past and you grew up.
With a background such as this should not be difficult to remember something of value that could be brought up in your speech. During your speech always try to sound natural. If you are normally not a humorous person by all means do not try to be funny. If seriousness is not your thing then simply do not present your speech on a serious theme.
Relating tales from your youthful days are great for including in your speech however make sure that they are relevant to the event at hand. Do not come up with something off the wall and expect it to blend into the setting as it simply will not do. Your speech should focus primarily upon your sister and not on the groom as the best man speech will cover his aspects of the wedding. Do not rush and do not overreact when presenting your speech.