This is all my own opinion.
But.....
Superb website & the kits do look wonderful.
But parents tend not to buy things like this for their own children. Craft kits for home are nothing more than paper, glue & felt tips from Wilkinson.
The people who WOULD buy stuff like this are, for example, slightly well-to-do parents getting a gift for their child to take to a party. Or brides might put these out for children at weddings to keep them busy.
I honestly don't know how online selling works - but can you make yourself available on Amazon & Not On The High Street etc? Plus on various kids party retailers sites?
Oh - and I used to be a copy writer specialising in search engine optimisation (which is what these people are trying to sell you). Don't pay them a penny.
All you need to do is write several articles yourself for your website using key phrases that you think various people might use - "wedding goodie bags for kids" or "great party present idea" - stuff like that.
But well done, I think your products & site are really great :)