Translation:I like talking with my sister in the afternoon.
"to" is still quite normal in the UK. Americans are more sensitive to the danger of "to" sounding like haranguing, and we in the UK, as usual, are starting to conform with the US. But there's nothing wrong with "to". I expect it was the archaic-sounding "after noon" that Duolingo marked wrong.
Why do you add "a" at the end of your transliteration of بَعْد? And I must say, it was a shock, after getting used to Arabic aversion to having two consonants together, to come across TWO words with adjacent consonants: بَعْد and the ending of ظةز (I don't know why the ه didn't change to medial form)ز
Both earlier commenters possibly mistyped. It should be ba3d. As for the transforming letter in DHuhur, this one is not the tied up "t" letter, but another letter that doesn't transform so much, notice the missing two dots. It's a silent "h" at the end of a word and sentence, but pronounced otherwise. That's my understanding. Probably more to it.
Ibraahiim13, I'd love to understand what you mean by "the transforming letter in DHuhur". I thought it was DHuhr. Hence my remark about "two consonants together". But since then I have come across two adjacent consonants in other words, so I'll stop querying it. But, really, I would really like to know which letter you are talking about in what you spelt as "DHuhur", the "letter that doesn't transform so much"?