There’s many ways of contacting Lilith, and one method is the Letter Evocation Method. If you click that link, it will guide you thoroughly, step by step of how to proceed to find what you’re looking for.
Of course you have to make a few changes to find a nurturing motherfigure, rather than a personal demon lover. You can also add Lilith’s sigil to make it even more potent. Maybe use the sigil of her in your necklace?
I’ve been very sparse in offering her gifts, but she’s known to like red wine, so that might be something to consider if you can afford it.