I would get a male because your female Dachshund is the leader. Once females fight they tend to not forgive and since your female Dachshund has fought a female before I feel your best bet is to get a male. Males fight too but they usually get over it.
Sinister "The Prince of Darkness" 4 yr old black male GSD 3.11.09
Draco "Dakota's Unbreakable Vow" 5.5 mth old male Dalmatian 6.30.13
Cats: Chaos, Mayhem, Monster, Wicked