Here is the full list of all 17 XP Girls achievements.
Complete Level 1 Fusion
Reach Level 10 With Any Character
Unlock Second Character
Defeat Level 20 Boss
Unlock Third Character
Have 1K HP On Any Character
Reach Family Level 50
Defeat Level 40 Boss
Do First Birth
Reach Level 100 With Any Character
Deal Over 100K Damage With Any Character
Defeat Level 90 Boss
Reach Family Level 400
Defeat Level 190 Boss
Defeat Level 200 Boss
Reach Rebirth 10 With Any Character
Reach Family Level 1800