Legalities of Browser Choice?

I have been working on an operating system, based off of Ubuntu, that will be based around young children. To offer them more choice, I decided to add a screen during the basic installation called the WIC(Web Interpreter Choice). On this, they can choose their default browser. After their choice it can require the admin pword(Something that I added, allowing the installation to be bounded by admins by modifying the installation files when downloading), followed by a request for confirmation of the terms and agreements of the browsers. It this legal? If no, what must I change to allow the person to choice their browser instead of defaulting to FF, as Ubuntu does.