My gf likes to feel small by being picked up. Idk if telling her the work to do that will make her feel insecure or be sweet, should I tell her?

So her(6'1) and I(6'4) are both pretty tall and one thing she mentioned she likes is feeling small with her partner. Earlier in our relationship, I tried picking her up and other stuff I've done with exes who were smaller and I couldn't do it.

I've always been fit and athletic (regularly work out) but at her height it ain't easy picking her up so for the past 6 months when I hit the gym I've been doing it with the goal of being able to pick her up and toss her around a bit.

Now that I'm confident I can, when I do it I'm sure she'll ask me where this came from. Idk if I should mention the time I spent training for her or if that would just make her self conscious about her size.

For background she is fit but tall, so she is inevitably heavier than the average gal and I know she had some insecurities about it when she was younger and I know a small part of that is still in the back of her mind even though I always tell her how attractive I find her and her long legs.

Heavier women how would you feel about this and would you rather know or not?

Tldr: gf is tall and likes to feel small. I worked out to a point that I can pick her up and make her feel small. Should I mention the training or just act as if it's no big deal?