I am currently in my second PhD year but my first year of research. Having left my job as a scientist for the APHA (and the Environment Agency before that) I started at the University of Exeter in 2018. I regularly receive comments on the lines of 'oh wow, must be tough doing a PhD and being a mother' or 'how do you manage with a PhD and a child'. But compared completing a Masters degree while working full time, and writing up my dissertation with a newborn (all of which I've had to do), managing to carry out a PhD as a mother to a three year old is far easier.
For me, it is no different from another normal working parent; work during working hours and family time with my husband and son around that. Due to the flexibility of a PhD I actually find it easier (compared to being in full time employment) with balancing work and family life. However it does mean being away but I am lucking to have the support of family.
Can you be a parent and carry out a PhD? Well I haven't finished yet, but so far it has been fine for me. I do feel a PhD is my second baby (it takes a lot of hard work, a lot of time, and is basically your life, but the reward is also great), but still manageable with a family.
However I understand my experience will not reflect other peoples.