I had my first when I was 31 and just had my second when I was 42. Pregnancy and labour I feel second one actually better and smoother but no doubt its more tiring physically. For me biggest difference is taking care of newborn, its so much more tiring now than 1st child especially with the sleepless nights and pumping. For my first I ebm for 1.5 years, for this baby I target 6 months and already finding it a struggle now as its really physically draining and to do it every 3-4 hours and restrictive for my job and life now as well.
My first born I got pregnant in early 20s and now am pregnant in early 30s n yes there is difference as during younger time more active do this n that now whatever I do have to be in moderate as body tired out easily. So it really depends on your body. Just listen to your body and you will do fine.
I personally feel age is not a factor. As long as doctor say you're healthy enough to bear a child even if after 35 years of age then there shldnt be any complications. Please consult your doctor for more expert advices..