Is It Safe To Have Melatonin Supplements While Having BP Medicines?

Hi, I have a question in regards to medication my grandmother is taking. She is currently on two High Blood Pressure pills; 1) Benazepril 10mg 2) Amlodipine 5mg but she is only sleeping about 6 hours a night which is bothering her during the day, she s exhausted, sad, not much going on for her so mentally no sleep is wearing on her. I looked up the effects of these medications which seems to be a calcium- channel blocker and a beta-blocker, both of these inhibiting melatonin which I believe is used to help regulate sleeping cycles. Hopefully you can verify all of this for me because I am not entirely sure how accurate it is, but I am debating having her take a melatonin supplement the only thing is Im unaware of how they will react with her body? If you could help me understand these medications and their interactions and then your opinion on whether or not it would be okay if she took the melatonin supplement that would be great. Thank you.