Yakuza is the king of returning characters. There are some that show up in Yakuza 4 that have not been in it since Yakuza 1 (guy you first beat up in the opening scene of Yakuza 1 makes a comeback!). Ryuji Goda hadn’t been in it since Yakuza 2 he showed up in Dead Souls!

I definitely wouldn’t rule out the possibility of her return but given the worlds they’re from it would be bitter sweet.