Q: For a funeral and wedding during the Lent Season, are we allowed to have flowers in the church for the celebration?
A: GIRM 305 forbids “for the altar to be decorated with flowers” during Lent, but it makes an exception for Lætare Sunday, Solemnities and Feasts. Since weddings may be considered the equivalent of feasts, including the Gloria during a wedding Mass even on a Lent weekday, I see no problem with flowers for weddings during Lent.
The GIRM does not speak about flowers at funerals. But the are Masses for the Dead, and in our culture flowers express mourning, rather than festivity. So in my opinion flowers are not out of place at a funeral during Lent.