You need to stop feeding them from a bottle now they've had their colostrum and got through the first day. If you keep feeding them, they will quickly stop trying to use the udder.
Get them penned with mum. If mum is not avoiding them latching on, they'll almost certainly sort themselves out in a confined space. If she's still avoidant, you may need to go into the pen and hold her steady every 4-6 hours so the lambs can feed. You won't need to do it for long, she'll settle down after a few feeds and you'll start to find the lambs not hungry when you go in.
(As you only have 2 adults, you will probably need to pen the other sheep next to the family, or it'll be distressed on its own.)
Do *not* give in and bottle feed.
If they don't seem to be finding the udder even when you hold the ewe steady, you will have to help them maybe a few times. Concentrate first on the one that's trying; once one is feeding the other will copy, and if not, once one is flying solo you can help the other.
To hold the ewe steady for the lambs to do their own thing. I find it easiest to hold her gently but firmly against the side of the pen, using my legs and bodyweight to press her, one leg in front of her hips and the other next to her shoulder. If you can get her nose in the corner, that helps stop her trying to exit forwards; otherwise gently hold her head horizontal with the flat of your hand under her jaw.
If you need to help the lambs on, if you have a helper, one of you can hold the ewe steady while the other gets down to help the lambs. It's harder on your own but the principle would be the same, get the ewe with her nose into a corner the use your bodyweight to press her (firmly but gently; she needs to know she's held but not be squashed so much it's uncomfortable for her) into the wall.
To get a lamb onto the teat. Get the teat operational (ewe dropping the milk) and get some milk on your fingers, let the lamb suck the milk off your finger so that it's making suckling moves and it has the taste of the milk. Now try leading it to the teat using your finger. Don't pull its head, it'll just fight, and once it's fighting, it won't be interested in feeding. So keep it calm, give it reassurance, don't bully it or make it feel manhandled. If you feel yourself getting frustrated, take a pause and let everyone relax again. If necessary, hold the lamb roughly in position by using your body behind it, to give it nowhere else to be - but gently, don't make it feel imprisoned or it'll just fight you. Keep leading the teat into its mouth and if you can, squirt some milk into its mouth.
Do *not* give in and bottle feed.
Even if you are unsuccessful, do *not* give in and bottle feed. Come back and try again in an hour or two. Keep your cool, you'll get there!