I truly hope you take the wise advice the previous posters have given you. Barging in unannounced is no way to start off a new relationship. Treat your birthmother the way you would like to be treated...with some respect. I'm just afraid if you show up unannounced that your birthmom will go on the defensive, especially if you have three other people in tow.
Yes, you have the moral right to know your history -- that's a given. But your birthmother has some basic rights too. Namely, she deserves to be treated respectfully and decently. What a shock it would be to have your long-lost child suddenly show up at your front door with no warning. Your birthmom needs to prepare herself for the initial face-to-face meeting.
Personally, I think you should call her on the telephone if what you're scared of is that she won't respond to a letter or email. Give some thought to what you want to say to her beforehand. Remember that she is a human being, just like you.
I wish you all the luck in the world on your journey. I'll keep you and your birthmom in my prayers.
