Yes, you can include your 2-year old daughter in your application as a dependent, and she will be eligible if you are to start the application process now.
Can I include my 2-year-old daughter to my UK investors visa application?
We understand that UK investor visa allows us to include any children between the ages of 5 and 18. Our youngest daughter just turned two. What would the process be if we want to start the application now? Will she be eligible by the time we submit the application?
Children up to the age of 18 can be dependants on the Tier 1 Investor visa.