Your not the only one.
They never really looked alike to me, in the manga Kagome had a more softer and gentler look, but the facial structure looked nothing like Kikyo's, Kikyo looked more rougher when drawn.
In the anime, they similarities totally are thrown aside.
Personly though Kagome always reminded me more of Midoriko from the anime version, too bad she wasn't actually seen in the manga version, because I could make that connection. Though I did have a theory that Midoriko and Kagome might indeed be reincarnation. It's very possible when you break down everything that happened and peice the peices together.
But yeah, I really didn't find any similarities, Takahashi even after the anime came into play, she adapted her characters to the anime look, my guess is she never intended for them to be similar in the first place, but who knows what was running through Takahashi's mind as she was drawing all of this.
♫ They see me trollin', They ragin', Patrollin' and try'na catch me writin' derpy. ♫