Good lord, some of you need to get back over to AIBU. This is parenting and I'm asking a perfectly reasonable question.
Just to reassure everyone (I understand why you might think this). DD is not doing this because she's not getting affection elsewhere.
I completely understand she is feeling a bit insecure etc with the new baby, and it possibly stems from the fact that when DD2 was born I was in and out of hospital for the best part of two weeks while DD2 was in NiCU and then readmitted. Outside of the constant kissing, I am still giving DD1 cuddles, kisses, we tell each other we love each, I praise her for good behaviour or doing clever things. I do bed time with her probably 4 nights out of 7 and even when I don't do a full bedtime because DH is doing it, I'll go in and say good night. She has a very hands on dad (although he does have to travel a bit) and she has very affectionate and engaged DGMs. She is not doing this because there is no regular affection she is doing this in addition to regular affection.
I've asked for advice because at the moment I am grinning and bearing it and I would hate to end up snapping or shouting because it gets too much. I also think it probably is a good idea to teach her about bodily autonomy (after other posters have articulated this) but i want to make sure I do it properly so she doesn't get upset.
For those of you telling me you feel sorry for DD well if you are OK being suddenly kissed in what are unusual (leg) or intimate (back of neck) places, several times an hour, without warning then well done, you're better than me. For the poster who said what is wrong with telling me she loves me, absolutely nothing, but I cannot overstate how much DD1 talks (it's from the moment she wakes up til the moment she goes to sleep. she's the sort of child who doesn't get tired. she's either awake or asleep and there's no in between), and if there is any break in conversation she says it, I think to fill the gap, and it can 10 times plus an hour, that combined with everything else is just a bit overwhelming.
Thanks to posters who have given understanding and constructing advice, I really appreciate it. I was just feeling a bit overwhelmed this morning as I have DD1 and DD2 on my own today, but we are off to the park now for her to run off some steam.