First of all... let me tell you, though there are books and people that claim that they can potty train your child in a day, or a week or whatever... YOU and YOUR CHILD KNOW WHAT IS BEST!!!
My daughter was three and not fully potty-trained. I was getting flack from my mom, my dad, my aunt, my brother, her daycare... and often, pressure from surrounding sources can be more powerful that what your instincts are telling you.
She just wasn't ready.
I didn't realize that at the time, however, and I pushed. My husband and I both pushed her. All it did was drive her away from her natural desire to control her potty-goings.
She had bladder control, we knew this because she would go hide in her room to pee or in the closet if it was number two (yes, her CLOSET!) when she had to go. She'd have an accident, then come tell us about it. It was going beyond frustrating. Now it was gross.
I was upset. This is my first child, and I felt hopeless, and I felt like I was going to have a 5 year old who pooped her pants in the closet.
What it came down to was her personal style of doing things. We had pushed her to do it our way, forgetting that she is at the age that she is becoming more independent and she often has her own way of going about completing tasks.
Soo... One day, I asked her if she had to go potty... she told me, "Yes, Mom." and started walking to the bathroom. As we got there, she turned to me, put her hand up in 'talk to the hand' form, and said, "No. You stay here."
She went in there, did her thing, and came back out. It was at that moment that I realized that I had done it all wrong. I had wanted it done my way and in my time. I'd forgotten what a strong-willed, independent child I had.
Since that day, we haven't had a single accident during the day. We've had three night-time accidents, but it's been some time and now she even wakes up at night if she has to go, does her business, and goes back to bed. Amazing. Leaps and bounds from where we where.
So, in my mom-opinion, what it comes down to, is pay attention to what they seem to want. Don't make the potty intimidating like I made the mistake of doing.
Don't set a date.
Just start, and see how she does.