Hello there. My wife runs a small business and like your niece we do not have a huge marketing budget. Might I suggest:
i) Buy a domain name. It's an annual rather than monthly cost, and if you do it through the right sort of site like freeparking you will probably get some sort of holding page as part of the deal.
ii) Create a Facebook business page. You'll need to read round that a little, first time I tried it got rather tangled up. But - it is free. It's easy to add content to, and people can comment. You can update it anywhere. Did I mention it's free?
iii) Create a Twitter account. Follow other local businesses, people you know, use it as a tool to provide offers etc. It's free.
iv) Remember the domain name from (i)? Add a link on the holding page to the Facebook page and give the Twitter details.
Ta da. Webpage, social media, sorted. Only the web page will cost money, and you don't even necessarily have to have that. Might just help with Google searches and the like. Hope that helps. This is what I did for my wife:
BooBoo Cupcake