Yes, there is mention of hagar being a wife:
Gen. 16: 3 And Sarai Abram’s wife took Hagar her maid the Egyptian, after Abram had dwelt ten years in the land of Canaan, and gave her to her husband Abram to be his wife.
Further, a little tidbit I just noticed...
Sarai acknowledges God's hand in her barrenness, and considering the promises to Abraham, she does what is certainly within the law, what her parents had done, what her children and grandchildren did...
Gen. 16: 2 (1-3).
2 And Sarai said unto Abram, Behold now, the LORD hath restrained me from bearing: I pray thee, go in unto my maid; it may be that I may obtain children by her. And Abram hearkened to the voice of Sarai.
Sigh...
She BLAMES GOD for it
Sigh...
She BLAMES GOD for it!
and considering the promises to Abraham, she does what is certainly within the law, what her parents had done, what her children and grandchildren did...
She did NOT believe the 'promise' for she had LAUGHED at the very mention of it!