My girlfriend is taking a long time to "warm up" to me physically after getting out of a long relationship, how can I help?

Patient. Patients will go a long way in solidifying the relationship in terms of her issues of working through loss.
Talk. Be open and honest with your girlfriend about your feelings, your thoughts, your fears, and ask questions about hers. You will learn how to work through it together once you know where each other is. Honesty and communication is a critical part of making a relationship last.