No, it's a semi-pseudo 50/50 because at one scenario Ivy attacks with the full string of 2,1,3 which is a Mid, Low, Overhead string, and in the second scenario Ivy cancels the 2,1 part of the string into Datura Hammer (D, D + 1) and gose for the Low version afterwards.
But here is the thing
@HeroesNZ, this is only a semi-pseudo 50/50 because in a real 50/50, you don't cancel a string to a stance move like Datura Hammer to get one of the options (overhead or low) while for the other option you just go for the full string. Even in a pseudo 50/50 you take a string that can be split into two options without using any other extra move to create one of the options. If the Datura Hammer had both an Overhead and a Low, then you would be able to cancel the string into the Datura Hammer and go for either option and that would be a pseudo 50/50.
An example of a pseudo 50/50 is that in MKX, Ninjutsu Scorpion has a 2,1,2 string, with the second 2 being an Overhead with the 1 can be canceled into Takedown which is a low. That way you go to either an Overhead or a Low with the exact same amount of hits and inputs before you go to the splited scenario.
A real, true 50/50 is when a character has both a Low and Overhead starter option that can start a combo, as that the first hit itself is already enough on it's own to be splited into 2 options, even if one option or even both can lead to just a small amount of damage. In MKX, Reptile has the B2 Overhead that can lead to a combo with B2,1 mid-screen or with either F412 or 414 in the corner, while also have B3 Low that can lead to a full combo if you have meter or just go for 4 to have a string is safe and very powerful for just one string.
As for Poison Ivy in IJ2, the only way she can have a real true 50/50 is if she picks between F3 (Overhead) or B1 (Low), but the F3 is very slow and can't lead to a full string or be special canceled like B1. So while it is technically her true 50/50, it is not a good one. In MKX, Liu Kang has and B2 (Overhead) and F4 (Low), with only the F4 can lead to a string or be special canceled while B2 can't do either, but Liu Kang's B2 in MKX is way faster then Ivy's F3 in IJ2. So even though just option for him can lead to a very small amount of damage, it is a true 50/50 that is still good as both options are fast enough.
Also for Ivy, she can't go for a pseudo 50/50 either as she has no string that can be split into two different options of Overhead and Low and she has no special that hits either Overhead or Low, except the Datura Kick from the Datura Hammer stance in which she has to go for that stance first before going to the Datura Kick.
All this combo does is just pressure. That's not to say that it isn't a good pressure, but a 50/50 it's not.