In this poem, the author is walking with her mother out into a field to see a newborn baby llama. It has rained and the fields are very muddy. The author says:

16.  along its back. I'm afraid

17.  he'll knock my mother over.

18.  Suddenly this winter she's unsteady

19.  on her feet. He runs to her

 She is an older woman and unsteady on her feet, so the lively black lab presents a danger to the mother.

I also think lines 23 and 24 express concern for the mother:

23. How little time

24. we have to love each other.

The daughter realizes that the mother is aging and time to love each other is running out. This shows that the daughter wants to show love to her mother and that would contribute to any mother's well-being.

Finally, line 30 says:

30. My mother's arm in mine, we turn back,

This shows that the daughter is supporting her mother as they walk in the slippery mud, making sure the dog does not knock the mother over and making sure the mother does not slip.