Only you can answer this OP. I’d take into account:
your health and fitness and weight (kids are hard work);
is marriage to dp on the cards?
will dp pull his weight as dad?
What happens if the relationship fails, would you want to be single parent to a baby?
How might dc1 react to a baby half sibling?
are you likely to be torn between baby and elder care?
are you likely to feel anxious about being “old mum” at the school gates?
I had a baby after a gap age 43. My mum was 40 when I was born, so I’m fully aware what it’s like to be/have an “old” parent. There are pros and cons. For me, it’s an absolute joy to have a young child in the house - I don’t find it overall more exhausting than when I was in my early 30s , I work hard at staying fit. Lots of swimming and running.
although, it is HARD being perimenopausal (insomnia) when you little one comes stamping into the bedroom and wakes you up with a beautiful grin at 6am every day!