What should the groom’s sisters wear to a Khotba in Algeria?

Hello everyone,

My brother is getting married soon and we are preparing for his Khotba (marriage proposal) in Algeria. I am his sister and i really need some advice on what to wear for this occasion ( i want to know for me and my sister ).

For context, we are part of the diaspora living in Europe. Even though we visit Algeria frequently, we have never actually experienced or participated in a Khotba before, so we are a bit lost on the exact protocol.

We really want to find the right balance. We are afraid of overdoing it (we definitely don't want to upstage the bride!), but we also don't want to look underdressed, neglected, or disrespectful to her family.

Originally, we were just planning to wear normal, classy "going-out" clothes (elegant but nothing too crazy). However, we wanted to ask you guys first to make sure this is acceptable.

Any advice, tips, or do's and don'ts would be incredibly helpful. Thanks in advance! ( Also, we are from West Algeria ).