Thanks for waiting for me. I too have emergencies, even rather frequently, because I am sole caregiver for my disabled wife and disabled daughter, and between them they'll have more than 2 medical and/or emotional emergencies every month.
Now to your dream. Your response is very helpful. First I will ask a few more background questions, which I would prefer that you answer BEFORE I offer an updated interpretation of your dream.
For me, dream interpretation is rarely just "reading the symbols, as if it didn't matter at all who YOU are and what's happening in YOUR LIFE at present. It's a matter of successive approximations that only succeed if we keep talking long enough to keep correcting for my inaccurate assumptions, usually based on inadequate information about both your personal life context AND the precise sensory, mental, and emotional details in the dream itself.
Questions: 1. How old were you when your mother died?
2. Was she happily married at that time?
3. How did your father and the rest of your close family respond to her passing? How was your grieving managed--by others or my yourself?
4. Are you married, or deeply involved with a relationship partner (of either gender) at present? If so, how do you feel about that person & relationship?
Now on to the dream itself: 4. How did the Green of the wood barricade/fence look&feel to you? Was it a natural color, like grass or new bush-growthshoots, or tree-leaves or evergreen foliage, or Spring plants? Or something unnatural, garish and repulsive?
And the dream's context in your present life: 5. Is there any upcoming issue in your personal life -- perhaps something potentially dangerous that may require a choice on your part that could have long-lasting consequences? So that this upcoming issue could appear as a Challenge or Barrier?
Now back to your dreams again. As a Jungian dream interpretation specialist, I believe that dreams DON'T just come to show us something we already know, but to show us (symbolically) something we don't yet realize, but need to understand in order to lead our own lives in the direction(s) that are best for us (and most Higher-Wisdom--aka God--directed).
You say that your mother has probably come to you in these dreams to transmit a warning--presumably about your near future. This time your dreams came three times. It's a classic facet of Folktales that the third try is a charm, that the third or third daughter is the one who solves the problem that nobody else can solve. But in your third dream YOU can see PAST your mother's head in front of you. You can see ahead the barrier that she cannot see. And YOU say to her "Mom we are going to hit."
In dream symbolism "SEEING" symbolizes becoming consciously aware of what is being seen, and by psychological extension, consciously realizing something that has always been unconscious before. And once you're conscious of what's in your way, you can involve your conscious mind in equal partnership with your unconscious mind (whose usual purpose and method of operation is to keep up our momentum by guiding us in solving every issue that comes our way in the same ways--according to the same habits--that we've always done before.
That's why you're jostled and shaken-up by the accident each time, but always comfortable afterwards. For this sort of "accident" (meaning unforseen crisis-collision-with-some-damage) and subsequent restoration of your comfort-zone is familiar to you: that is habitual.
So the key to the unknown meaning of this dream, and to its potential for guiding you towards a significant change in your life, is this: 5. (rephrased) WHAT Event(s) (quite possibly known or unknown to you at present, but coming in the very near future) or also Thought(s) & Feeling(s) seem similar enough to this "Accidental Jolt-from-a-barrier" to have triggered your dreams?
I have a pretty good guess about what sorts of oncoming events could trigger your dream. But I'm wrong about as often as I'm right, and I don't want to take away the thrill of discovery from YOU, the dreamer, to whom this potentially life-changing revelation rightfully belongs.
I just spotted another phrase in your responses that might add to this dream's meaning for you: 6. Is there any aspect of your childhood upbringing that could have felt like "being shuffled back and forth in the backseat" of the family car? (My wife experienced something like this at the age of 11, as 2nd child between older sister 13 and brother 9, when their father suddenly died of a heart attack at work, and nobody was allowed to grieve after 3 days. Perhaps your grieving was also squashed by adults.)
You really do deserve the revelation that your dreams are trying to give to you, and it's worth way more than this website charges you. So just hang in and answer the 5 questions I've posed this time, and we should reach the finish line, with hopefully enough evidence in print to reveal the truth and value of how your dreams are working for your freedom, well-being and psychological&spiritual development.