Sourcing any image that is not yours is mandatory here on Hive since you are making money from your posts. If it's not your own completely original content... then it's considered plagiarism. If you find art that you like and want to recreate you need to post a citation or source to where you are getting your idea and inspiration. Otherwise, it appears as if you are trying to make it look like your own. You did mention finding this on Facebook... but that's not enough of a citation or source.
You also posted this art more than once which is taking advantage of the rewards pool. You received a message the last time you posted this artwork about it being plagiarised and you didn't comment back there. That doesn't look good. Read the comment i left for thebusycat above and you will know my thoughts.
I made two posts that go over a lot of the dos and don'ts for Hive. Maybe you could all spend some time together going over these issues so as not to break the rules any further.
Please check those out when you get some time and make sure NOT to do the things in there it warns against doing.
You are absolutely right and im sorry.
Just know that nothing i have said or done is personal. It's more of a professional courtesy to the community. Please do read those posts and take some time to get familiar with the unspoken rules and etiquettes for how to be successful here on Hive. Using the best practices is actually more rewarding in the long run in more ways than one. Doing things the right way is going to help you succeed. I want everyone to be successful here... so long as they aren't scamming or abusing the privileges that we are afforded on Hive which can enrich our own livlihoods. Cheers Karen.