Lacking Self-Confidence

Question:

I am the mother of two children, an 8 year old son and a 5 year old daughter. My husband works out of town for 28 days and is home for 7 days so you could call me a part-time single parent. I also work 5 days week. 

My children are both lacking in the self-confidence department and I would be grateful for any information that could help them become more confident. For instance; if I ask a question such as would you like a red or yellow popsicle? – I get an “I’m not sure” or “what do you think”, or if I ask did you like the movie? – “Kinda or sort of yes and sort of no”, never a solid answer. If they are asked to choose an item it takes them forever to decide, even if it’s only 2 items.
My daughter will not speak to most people, she just hangs her head and shrugs her shoulders, even when we run into class mates at the store. Most people we know just say “oh that’s ok she’s just shy”, well then she plays it up even more. 
What can I do? 
Monica