With singular family members, Italian usually drops the article before the possessive:
So di mia zia is exactly what you would expect.
A useful contrast:
There are exceptions, such as when the family noun is modified:
Quindi means so, therefore, or thus.
It connects the two ideas:
It is showing a consequence or result.
Here le means to her.
The full idea is:
When Italian replaces a mia zia with a pronoun, it becomes:
So le is an indirect object pronoun.
Porto is present tense: I bring / I am bringing.
In Italian, the present tense is often used for:
So le porto dei fiori can mean something like:
If you want to make the future more explicit, you could say:
Both can work, but the present tense is very common in everyday Italian.
Dei here is a partitive article, and it means some.
So:
This is very natural when you mean an unspecified quantity.
Compare:
So dei fiori is the best choice if you simply mean some flowers.