Yeah, I'd say oats would be absolutely fine at this age... meat too, if you want.
DH and I had DD trying out solids from about four months, we were really relaxed with 'allergy' foods (dairy, eggs, peanuts etc, just handed them over and had the phone nearby in case we needed an ambulance, she was fine) and she lapped them up. 'Grown-up' foods like oats, weetbix etc really seemed to help fill her up too so she was much happier and started sleeping through a lot quicker than a lot of other bubs her age (although that could just have been our good luck, but it's something to consider if you value your shut-eye!!).
Just one tip when giving cereals like weetbix and oats, make sure she's getting a bit extra water/milk on the side because they can get a bit gluggy and clog up their little systems, which can then be mistaken for a gluten intolerance etc... so just give her a bottle or sippy cup of water when she's having cereals to make sure it all keeps moving along

With meat, we didn't worry much about mincing or pureeing, when she was about 5 months DH just cut off a chunk of his steak one night and handed it to her to play with in her high chair, she sucked all the juices out and gummed it to mush and absolutely loved it!! She still adores her meat, and at 17 months can sit at the table and use a fork to stab little pieces and chew them up herself. So I wouldn't worry too much about ages etc, if you think your bub is ready to give things a go (or just feel like a laugh, watching them try new foods is hilarious), just give her a big chunk of whatever you're eating and let her play with it, they don't eat much to start with and it does get messy, but it gives them a bit of practice and they feel included when they're sharing your food
HTH