Sorry to hear that, I lost a ewe when her two lambs were 5 weeks old this year.
Both are still alive after about 10 weeks, they had plenty of good grass and ad lib hard feed, but if I’m honest they’ve not really thrived as much as the same two lambs from the ewe last year. Just a bit too young to have been weaned, and they both have been persistent with dirty backsides vs all the other lambs too.
10 weeks should be alright for your lamb.
Good luck and all the best.
(If I’m being honest this year has been rubbish with the sheep as I’ve lost 3 ewes out of 10 and 3 lambs. Was just about ready to sell them all, and tonight I found one fly struck on his backside. Should be fine as it’s cleared out and sprayed, and hopefully it’s dry enough to spray the rest this weekend as it’s been bucketing every time I’ve been able to get by them. Apologies for going on, but it’s felt like one thing after another, hope 2024 is better).