Why Yamini doesn't have suryavanshi mark on her back?

As per S1 Yamini is sangram singh's sister and that means she also belongs to suryavanshi unless she is an adopted child and nothing of that short was mentioned anywhere in either season...then i am just wondering why Yamini don't have that special suryavanshi nishan on her like sangram singh, ritwik and other suryavanshis?😕...since it can't be said that only guys can have that symbol as shivangi too have that symbol on her back...is that means Yamini was not related by blood to sangram singh?

She was Sangram's step sister and hence not a suryavanshi.

Originally posted by: slippery_chilka

She was Sangram's step sister and hence not a suryavanshi.

Originally posted by: ramishi

Ok...but did they mentioned about this anywhere in either S1 or S2?

But step sister can have same father...so i think in this case sangram singh and Yamini's father are not same and she might be be the daughter of one of sangram singh's step mother from her earlier marriage.