Hey Caroline 🙂
I have checked out your ecom store and love the vibe of your business! I can understand your frustration around paying for advertising (through social media and google) and not feeling like the returns have been worthwhile as they are not hitting your expected targets.
After checking out your store I believe your product would be well recieved on Chooice http://www.chooice.co.nz . This is a great platform that currently has a following of 546.6k shoppers, majority based here in NZ and ready/wanting to support local business.
I would look at setting up a Chooice store with a few of your most popular products. Then utlise the posting abilty to post everyday from your business facebook about a different product that your store has to offer.
The Chooice community https://www.facebook.com/groups/Chooice love animals and it could be an awesome opportunity to make sales but also gain a following on your Facebook. Once you have gained this following you can create a look alike audience and potentially have more success and better reach via online marketing.
Chooice has created an phenomenal platform with incredible reach to active shoppers. Posting on the group page comes at no cost as well so it is the perfect opportunity to test the market with some simple advertising.
Hopefully this helps,