The nominative case of we is we. As a pronoun, us is translated into "we" and "I" in Chinese, which is the first person plural form and is often used as the object of verbs or prepositions; We, as our nominative forms and pronouns, mean "person" and "we" in Chinese.
The meaning and usage of the text introduce that we are pronouns, meaning "we" and "I". She gave us a painting as a wedding present.