Please Holy spirit be with me as you have been frequently of late...
The question posed by Fran was,is it necessary for a member of her family to be baptized again seeing as that they were baptized as a baby,well first off Fran I shall speak on the wise paul did,I apologize if what I say offends you but I shall not apologize for telling the "Truth".(also if you can't read my post feel free to edit it into paragraphs and etc,I shall try to be mindful of not doing a wall text!)
Here is your answer...a baby has no reason to be baptized for it is written,"if a child hath no parent then God accepts the child with open arms"meaning whether a baby is baptized or not if the child dies God accepts the child into heaven into his "arms",
A "true"water baptism is when the individual is aware of that they are being baptized not for mere membership to a church(the wrong reason to be baptized)but rather you accept Jesus's death for your sins and believe faithfully that from the baptism you shall be cleansed of sin through Jesus,(thereby being rid of your own sin as well as being free from adam's old sin)
so your family member,only if the desire a clean slate for themselves and truly believe that Jesus died for their sins shall they choose water baptism now being "able" to accept cleansing through water baptism,which is really in general terms starting over with no sin(yet still capable of sin)
but remember water baptism is only "water" if there is no willingness to begin life a new,just as to be saved is not to be forced upon anyone,neither is water baptism to be forced each "individual" must decide for themselves whether or not they will ask God to save their soul sincerely,accept Jesus as their saviour,and be baptized in water thereby being baptized into Jesus's death,and both are best to do for once going through both "Willingly" "anyone" can receive the holy spirit,who not only comforts but will teach one while one reads the bible,and bring to mind scriptures(as the holy spirit does for me ever so frequently now!)that you have read and know some about,
So to summarize no your family member does not have to be baptized but their first supposed baptism was not a "True" water baptism so this has currently done nothing for your family member where as if they are willingly water baptized now they will receive the blessing of what the bible tells of,a new start without sin.
Though as I said both are best to go through because anyone who does so willingly will not only receive the holy spirit but also be forever God's servant and thereby being in his hand therefore nothing nor noone can pluck the individual from God's hand,as in the devil has no more power over the individual and they are protected eternally by God,and "if God is for you,who dare be against you" so basically to further summarize an individual can have wisdom from the holy spirit,God's protection,and a sin free new start,"for whosoever believeth in the son is a new creature,the old is gone the new is come(not the exact scripture probably because I'm about to nod off)
so I have given what the holy spirit has allowed me to share with you,now you may decide what you believe and if you tell your relative they can decide what they believe,I have given you truth but no command for I am not God and as his servant can only speak in such a way that one understands baptism and salvation but shall never be forced by me in anyway for I be not a fool for I fear God who can destroy body and soul,so I dare not speak in a forcive manner,authorative and truthful yes but forcibly no,well I am fading into sleep fast,so I would last like to say I have given what I can to answer your question,Fran and I leave this all for you to ponder upon.(also as I said before feel free to put my post in a way that you can read it,because I'm too groggy it's 7 am I got off work at 3:30 and have tried my utmost to answer your question,so I'm going to sleep now...)