Letters are assigned to Mercury, and we have to look at the 12 spiritual house. interestingly Mercury is in the 12 house, which fits and asserts that we are in the right direction. Mercury is also in Gemini, which has the strongest association to communication and messages.
the Asc is in Cancer (family, roots, etc’), which fits your belief that this is a message form your grandmother. The Moon, your significator, is in the 8 house of death (someone who passed..?), also a somewhat spiritual house being the natural house of Scorpio. The Moon is in Aquarius, air sign that also implies communication, and will soon Trine Mercury.
So far, it appears that yes it is a message. The question is what this message is about, and for this we need to know some more details about you, your current situation, financial? Romantic maybe?
Let’s try anyways. The message itself would probably be transferred from this Mercury (communication, messages) in Gemini (again communication, messages) in the 12 house (spiritual). After a trine from the Moon (you), it will sextile Jupiter in the 2nd house of money, ruler of the 6 house of work and 10th house of career. Therefore I guess the message is regarding work. There are some clues here about the kind of jobs you need to choose from, but for this I’ll need some more details.
Interesting chart