you can strip her after about 18 days or so. If you can see fry then i would say its ok to strip her, but if she is on her own there isnt really any need too. If you do want to strip her then all you need to do it catch her in you hand and gently open her mouth with something (i.e a toothpick, as you said) the fry will swim out. Dont cover her gill plates as you hold her though