VJKK VJKF,
The maryada of giving gurti to a new born has always been practiced in my family, however, due to ignorance I have seen many variations on this practice. As Bhai Kulbir Singh has said, I don't see anything wrong with getting the aseesa(n) of a Gursikh in this manner. In our family, we look for a Gursikh family member/family friend to prepare the gurti.
The variation that most concerns me is what happens to the gurti after it has been to the newborn. My understanding is that five drops are given to the newborn from a sarbloh kirpan and then the mother drinks the rest. In some instances, I have seen the gurti be distributed amongst the gathered sangat and labelled as 'Amrit' (some members of the sangat then express concern that they will have to keep some sort of rehat at taking the gurti!). In some instances gurti is not prepared in the Hazoori of Guru Sahib, and in some Degh is not even prepared (substitued by the gurti). Damdami Taksal have detailed the preparation of gurti as follows:
"As soon as is possible after the birth-Amrit is to be prepared in the following way:
An Ardas (prayer of supplication) is performed before the start of the ceremony
An Amritdharee Singh should get a Sarab Loh bowl and half fill it with water.
Five patase should be added to the water
This mixture is to be continuously stirred with a Kirpan
During the stirring, the Singh is to recite Japjee Sahib from memory and is to sit in the ‘Bir-Asan’ position, a Warrior stance.
Once the Japjee Sahib recital is complete the Amrit is ready and an Ardas is to be performed and then the Amrit can be administered.
Your Spiritual Father is Sahib Sri Guru Gobind Singh Jee;
Your Spiritual Mother is Mata Sahib Kaur Jee;
Your Place of Birth is Takhat Sri Kesgarh Sahib, Sri Anandpur Sahib;
Your Maternal home (Nanakee) is Guru Ka Lahore;
Your Obedience is to the One Timeless Lord;
Your only Guru is Sri Guru Granth Sahib Jee.
You are not to bow or obey any other as your Guru;
Your examination is only via the Shabad and Gurbani;
Five drops from the tip of the Kirpan are to be given to the child and the mother is to drink the rest of the Amrit. This is the first ceremony of initiation of a child into the Khalsa Panth (Sikh Nation).
The mother is then to breast-feed the child, from this the child should become virtuous, a warrior, saintly, charitable and a vibrant Gursikh. Enacting any other sort of birth rites/ceremony is not allowed in Gurmat; for example lucky charms or strings tied on the child’s wrist or around his/her neck. To break all superstitions a Sarab Loh Kara is to be placed on the child’s right-hand wrist. Drinking alcohol and eating meat whilst celebrating the birth of a child is a grave sin.
After the above ceremony, Karah Parshad is to be prepared and an Ardas recited in the presence of Sri Guru Granth Sahib Jee. The child’s name is based on the first letter of the Hukamnama taken from Sri Guru Granth Sahib Jee.
If possible on the same day a Sehaj Paath should be started. The child and his/her mother should listen to the whole Paath. At the Bhog (completions of recital) Guru ka Langar is to be served to the Sadh Sangat (Holy Congregation)."
Above extract taken from:
http://www.damdamitaksaal.org/code-of-conduct#h1-birth-ceremony-janam-sansakar-first-ceremony