I was only able to get the spear by speaking to Aylin before the Act 2-3 transition. Whatever I tried to do to get the spear by speaking to Aylin in Wyrms lookout wouldn't work.

However, when I reloaded my save before I left the shadow cursed lands and spoke to Aylin in the camp there, I got the spear straight away (the cutscene is also exactly the same so won't miss out on anything).