This is similar to my BPD mother in her elder years after my father passed away. There were issues before that but my father was, to her, a stablizing force and he also was present with her- and with her behaviors.
Inititially, after he passed away, she didn't want much to do with me. On the advice of a friend, I still called her on a regular basis. Sometimes she would pick up, sometimes not. She still was active socially. She had enlisted her family members to "her side". I wasn't allowed to speak to her doctors either. I assumed she was fine (about as fine as she was with BPD). With my mother- her contact with me seemed to be mostly on her need basis- and she didn't need me.
Someone must have been concerned about her, as some time later, a friend of hers advised her to redo her legal papers and I received copies making me her power of attorney. However, I had no information about how to use this if needed. She kept her financial, and medical information secret from us. The only time we- her kids- would ever use it would be in an emergency, but we wouldn't even know what to do.
Some time after that, when visiting, we accidentally found out she had taken a home equity loan out on the house and had gotten herself in trouble financially. We took her to her bank to find out what was going on. The bank would not speak to us without her. Once we got there, she changed her mind. So we didn't have any information or way of knowing how she was. It was also about that time people began bringing up the idea of assisted living to her- as they were concerned about her being elderly and on her own. She refused.
Eventually- her family members became concerned about her and contacted me. BPD mother had convinced them that she was fine and I was the one with the emotional problems but they had seen enough of her behavior to be concerned that she was not OK. I told them everything. They were the ones who were able to get her to agree to assisted living. She didn't have a lot of choice, because she had mortgaged the house to the bank, and her funds were getting low. The house was sold and what was left of the sale after the bank took its share was to cover her stay there. Her BPD behaviors were still there but it was helpful to know that others were there to check on her.
In summary- this is how it went with us- and possibly with you too. While you care about your mother and feel a duty to check on her- she is in control here, and probably like my mother legally competent to make her own decisions, even if they are unwise ones. I even contacted an attorney to see if it was possible to intervene and as long as my mother remained legally competent- she could do what she wanted with her money, her medicines, her behavior, even if it was not in her own best interest to make these decisions.
While we kids would have prefered to be proactive, make sure her money was safe and available for her care, make sure she was in a safe living situation- this was not possible with her. The only time a change could be made would be in a crisis situation. This is stressful but BPD mother did not cooperate with planning, she wanted to be in control.
Yes, she did the things you are concerned about. Making suicide threats (call emergency for these). take Lorazepam as she chooses (let her doctor deal with that). Spend her money recklessly. As much as you are concerned and worried- and that is understandable- it's likely your mother will continue with her chosen situation unless some situation requires a change.
As the daughter of a mother with BPD. it's likely you have been made to feel responsible for her in some ways. Culturally, and in religions if you were raised in one- we are expected to step into a care role with elderly parents- and this is normal in many situations where an adult child takes on certain aspects of this. Your concern is normal, but this is not a "normal" relationship. If you aren't in counseling, I recommend it for your own support as this situation is distressing and it helps to have someone objective to help. If there is an ACA, or Alanon, or CODA group near you, it can help you to cope with your mother's medication use. It's hard to not want to intervene but if you are unable to, then there's little you can do.


