From hand written copy of the will provided by Nicky McSwain.

In the name of God Amen, the second day of April in the year of our Lord one thousand seven hundred and fifty eight, I Thomas Felps of Baltimore County, Planter being very ill but in perfect mind and memory, thanks be to God for it, therefor ___ my ___ mind the mortality of my Body and Knowing that it is appointed for all men once to die make and ordain in this my last will and Testament that is to ___ of ___ pal___ and first of all I give and recommend my soul into the Hands of God that gave it of my Body I recommend it to the Earth to be buried in a Christian Like and decent manner at the discreation of my [Executors] nothing doubting but at that general Resurrection I shall made the same again by the mighty Power of God and as ___ such worldly estate wherewith I hath pleased God to be ___ in this life I give, devise and dispose of the same in the following manner and form It is my will and I do order that the first place all my just debts and funeral charge to be paid and satisfiedFirst and foremost I give, bequeathed unto Rosannah my Dearly beloved wife all my ___ with my household goods and moveables to have during her natural life whom I so devise constitute made and ordain my only and sole Executrix of this my Last Will and Testament all and Singular to her.
Secondly I give and bequeath unto Aventon Felps my beloved Son, after my wife's decease the Plantation where I now live on and all the moveables which maybe found and Thirdly I will and bequeath unto David Mackswaine the Plantation where he now lives on, it being part of a tract of Land Called Arabia Petria which I bought of Isaac Webster, to him and his heirs forever - and fourthly, it is my desire that my negro man named Zuibitt shall be free from servitude after my wife's Demise and Fifthly I bequeath unto Hannah Mackswaine one mare colt of one year old and Sixthly, I leave Edward Morgan as trustee after my wife's decease to take in porsetion every things which may be found which will belong unto my son Aventon Felps, that to take care of it till he can acquaint him of the same willed and bequeath satisfied and confirmed this and no other to be my Last Will and Testament.  In witness whereof, I have here unto set my hand and seal this Day and year above written.

WIT: Wm. Huges Joseph Johnson Thomas Dr___

his Thomas X Felps mark

This is document does not make a connection between David McSwain and his wife Hannah.   There is, however, church records of St. George's Parish , Hartford County, Maryland showing the birth dates of Thomas and Jonathan McSwain and noting they are "Sons of David and his wife Hannah."  Thus, there is a basis for assuming the above Hannah Mackswaine is the wife of the mentioned David Mackswaine.