The appropriate thing to do would be to not use it at all until you contact and hear back from who it belongs to; in this case that would be
Starcanis. If you don't hear back, don't assume that is the same as a yes. It was made for HER and features HER EXTREMELY PERSONAL and beloved character and was never ment for anyone to just take and use how they see fit. Respect the art, respect the artist and have some consideration for the person that the art was made for.