Fungus under fingernail?

[mrspopo]

Our 1 year old has a lot of gunk under her fingernails because we've been slacking off with trimming them. So DH got busy holding down the squirmy bean so he could go at it with the clippers (did you know that it's really hard says DH... hehe yep). Much to his surprise there's 2 nails that have the gunk going down further than he can get with clippers. He's convinced this is a fungal infection, she does touch garden dirt sometimes ya know.

I googled fungal infections and it looks nothing like that. It just looks like there's regular fingernail gunk but it goes halfway up the nail bed. Any suggestions on what this might be? There's absolutely nothing that looks inflamed or irritated... no pink or white... just brownish gunk colored.