"Aunt Toma is where mom is."
Translation:Тітка Тома там, де мама.
Think of it as ‘Aunt Toma is there where Mom is.’. The word ‘there’ can be left out in English, but not (apparently) in Ukrainian. (In contrast, ‘is’ can be left of Ukrainian, and as far as I know must be left out, but not in English.)
This is such a strange sentence! I'm a fluent Ukrainian-speaker and I would never use this form of speech. It sounds 'incomplete'.
I would say: "Тітка Тома є там де Мама є." ("Aunt Toma is where Mother is.") It makes more grammatical sense...
The sentence "Тітка Тома там, де мама" is perfectly grammatical. We need to be careful not to impose grammatical structures from other languages onto Ukrainian. Ukrainian speakers who are not native English speakers do not use the verb "є" with this frequency, or (in particular) to talk about location. It could sound incomplete to your ear, but it sounds (and is) ideal to a Ukrainian one.
I understand it but it is clunky & awkward. It does not sound like something we'd say in English.
No, it's just means that they are in the same place at this particular moment