Smidt returned to TUKS in 2023 after a two-year spell with reigning Hollywoodbets Super League champions Mamelodi Sundowns Ladies.
Khumalo says they had to give Smidt a clearance.
"With Thalea, we discussed the matter and she requested clearance because of personal reasons and then she has to relocate to Cape Town. So, that is basically that, nothing else," Khumalo said.
The Pretoria side lost 3-2 to Royal AM on Sunday afternoon.
The university team has been struggling with consistency since the beginning of this season having lost 15 of their players which forced them to sign nine new players to beef up the squad.
Khumalo who coached the Banyana Banyana team in last year's COSAFA Cup believes her team can do better.
"My assessment for today's game was simple things, do you understand, just to keep it basic and then I realised that Royal AM were sitting back and it's something that we planned in the training session that we need to pass the ball to our wide side and force Royal AM to turn so we can play those tap ins,” Khumalo explained.
“We created three chances in the first half that we could have converted but I feel like some of the players don't take the game seriously. Even if when they miss the opportunity, it's okay.
“I feel like we could have wrapped this game in the first half and in the second half we could have scored the goals that we could have scored. I feel like we could have won this game 5-0 or 6-0."
TUKS will face JVW on Saturday.