Oh gosh, I'm so sorry to hear about your mother. I know this is going to be difficult but you should try to remain as calm as possible for the baby. If your mother's stomach is swollen to point that she looks 8 months pregnant, just imagine the agony and pain she must be feeling internally. Try to make peace with this reality by knowing that the pain, the agony, and the distress that your mother is going through is coming to an end. I don't know if you will be going to Cali to see her, but the best thing you and your family can do is spend as much time as possible with her and reflect upon what a great life you all have had together.
I actually feel really terrible right now because I cannot even imagine losing my mother and cannot fathom how you must feel. My mother has been my rock, my sustenance, provider of warmth, love, and nurture, and she's always been the person whom I can turn to. I don't know if you're a fan of Christina Aguilera or not but I always think about my mother when I hear the song "I Turn To You".
It's hard to say goodbye; especially when it's someone so important. I don't know what to say....it's hard trying to sum up and experience and share all that you wanted to in just a few days. I don't know if your family is religious, but I would see if you can get a religious leader (pastor, rabbi, iman, priest - according to your beliefs) to make a visit to say a prayer that you all could do as a family. I would definitely spend every waking moment with your dear mother, and I'm guilty of this too, but tell your mother everything you've wanted to say and would've wanted to say to her - let her know how much she means to you and just.....love. Make memories - take photos - share kisses and celebrate her life. I don't know how bad her condition is and if she's bed-ridden, but if she's physically-able, ask her what she wants to do and if there's any particular place or particular activity she wants to do. If she wants to eat anything? Maybe something from that ice cream parlor you and your mother may have gone to since you were a child? Something sentimental.
I'm so sorry......I don't know what else to say. I am sincerely sincerely sorry and I'll be praying for you, your mother, and your family. God bless you all.