I'm Lucy, and I'd be happy to answer your questions today. I'm sorry to hear that this happened.
To be charged with threatening someone, there are a couple of things that have to happen. First, there has to be a statement of desire to do someone harm - wishing someone is dead is not the same as intending to injure them. The more concrete a statement, the more likely it would be considered threatening. But teenagers have been screaming, "I wish you were dead" at their parents for decades; that's not a crime.
A threat also has to be immediate. something that a person appears to have the intention of carrying out immediately. Writing something on a picture rather than saying it directly to the person you're upset with doesn't meet this requirement. There's no evidence of a present intent to do harm OR the ability to do so, since the person wasn't with you when you made the statement.
Third, you're not likely to be charged with threatening because you did not convey the message to the boyfriend, nor did you ask your daughter to do so.
If you have any questions or concerns about my response, please reply WITHOUT RATING. It's important that you are 100% satisfied with my courtesy and professionalism. Otherwise, please rate my service positively so I am paid for the time I spend answering questions. If you are on a mobile device, you may need to scroll to the right. There is no charge for follow-up questions. Thank you.