Lauren's good but just that. Good. Very much overrated, I thought she'd be the shock elimination at Judges Houses. Her and Kerrianne were the only reasonably good singers at Judge's Houses - Kerrianne was the best singer of the 6 but Cheryl sent her home.
The standard of singing for female singers is quite high though - each year (except this year) theres always been a strong female ballad singer - Rowetta (series 1), Brenda and Maria (series 2), Niki (series 4), Ruth and Laura (series 5), Mary (series 7), Sami (series 8), Melanie (series 9) - then more successful ballad female singers who have had varying notable success and gone into pop are Leona (series 3) (probably the most infamous one), Alexandra (series 5), could argue Stacey Solomon (series 6) but she's had more success as a TV personality, and same with Sam Bailey (series 10). Then theres Amelia Lily and Misha B (series 8), and of course Ella Henderson (series 9). As Lauren stands as the strong female singer this year in comparison with these she's fairly average tbh.
If Kerrianne was sent through to Live Shows I'd imagine she'd still be in the competition now.
EDIT: I consider Misha B, Fleur (current series), Alexandra Burke and Cher Lloyd as more performers than or as well as singers, especially for Misha and Alexandra.