Apparently her actions (suicidal comments, etc) caused you to naturally inform someone. Likely she was trying to control you - suicide threats are either real contemplations or slick emotional manipulation/coercion to involve you - but you didn't fall for it. So now she's been triggered. Do you know why she's trying to contact you? While it would be nice to resolve it, likely she wont listen to reason, there's too much emotional baggage for her to get past that.
Sadly, 'closure' is a rarity in ended BPD relationships. Both have to Let Go and then Move On.
Hmm... .Can you try the least impactful steps first? Below is a quote from a few months back, since you've already asked her to stay away, start with just a neutral lawyer notice letter or a police officer to ask her to leave you alone. Only after such efforts fail would you take the bigger step of court action. Why last? Because that's when the ante is upped and she may try to make you look worse than her by making allegations.
You may want to consider taking it in steps. First, next time she makes contact, ask her not to contact you ever again, be firm, don't leave an opening for 'sometimes'. Or if you don't want to wait you could respond to her latest contact and tell her to stop. Second, maybe a letter from a lawyer might have an impact that you alone saying No didn't accomplish. Third, seek a no contact order or equivalent from the court. Be aware that court ignores older incidents as 'stale' and not 'actionable', except to demonstrate a pattern of behavior. So if she does something that you consider is actionable, don't wait too long to seek a remedy.