Ask Lilith telepathically, but don't be demanding or impatient. She's very busy and will get back to you when she can. When I ask my Guardian Demon/ess something, I usually get an answer within the day, to three days. It depends on the importance and urgency of the question (to them).
Our Guardian Demon/ess is always willing to remind us, usually more than once, that they are our Guardian, through different means. When I was super new, my chief Guardian Demoness Marchosias told me, in my head, more than once "Marchosias" and I wasn't sure if it was her or the enemy (I was already open to telepathic communication my whole life, and was already dealing with enemy Greys). But she would come to me, through astral projection, to where I was sitting at the computer and guide me to posts by other members in the Joy of Satan Yahoo groups (this was about under 10 years ago, before these forums) and they would mention her voice, attributes, and other characteristics. I became more sure of her, and started communicating with her more often.
I will tell you something that my good spiritual Satanist friend told me about Lilith: if she *IS* your Guardian Demoness, don't go around bragging about it because she's high ranking, popular, powerful, etc. etc.
Don't show off.
She's very private and secretive and she WILL make you keep it a secret if she is actually your Guardian.
Of course, this relationship differs from Demon/ess to Demon/ess. I know my Guardian Demoness Marchosias likes me to make mention of her and Satan here and there in the posts in these forums and Yahoo groups in the past.
I'm just relaying what I was told, and experienced to be true. Just to be on the safe side (regarding Liith's privacy)
I am passing it onto you.
Of course, there are no intermediaries in Satanism. I suspect you might be new, (I might be wrong) so please don't ask me to talk to Lilith and get back to you, or anyone else to ask her. It's on you to talk to her, yourself. She is blatant and clear.
Have no expectations or assumptions on how Lilith or other Powers of Hell will answer you. It's usually clear, blatant, and a positive coincidence. You will notice. Just be open and aware.