1- We have many hadiths that crying for Imam Hussain (a) makes Lady Fatima (a) happy, and it reaches Lady Fatima:
كامل الزيارات عن الإمام الصادق ” عليه السلام ” قال : ( وما من باك يبكيه إلا وقد وصل فاطمة ” عليها السلام ” وأسعدها عليه
Such hadiths indicate she is aware of the Majales, because when we cry she knows about it.
2- There is a hadith that indicates (in an incident) Lady Fatima (a) attended the Majlis of Imam Hussain (a), but the hadith does not have a chain in our early sources. However, since Lady Fatima’s soul is alive there is nothing wrong with believing that her spiritual presence exists in the majalis of Imam Hussain (a).
3- We don’t have any hadiths that states she collects the tears. This maybe based on a dream.