Impossible to quantify, completely subjective.
We don't love all of our own species the same, and what IS love anyway?
If love is the feeling you get from a range of hormones, then the truth is when you get a puppy or new dog, most people experience a rush of oxytocin (so does the dog) from that bonding experience, from cuddles, eye contact etc etc.
That is the same experience people get with their babies.
But that isn't all love is, do you get a rush of oxytocin from looking at your partner, no, your best friend, no... but do you love them, yes.
Isn't it enough to say we are capable of loving not only our own offspring, but other members of our own species AND members of other species and some of those species are capable of some degree of reciprocation.
Do we have to quantify it, label it, set it out as better than, more than, less than anything else?
I see the 'well yes but I'd rescue a child from a burning building before I'd save the dog'...
What if you had three children, which are you saving first....
It is a stupid premise, in reality, you'd do your best to save everyone, and likely you'd grab the nearest and lob them out of the house, not ponder over who you loved more!