1. Pattern-less function names.  For `Queue.h`, rather see function named  obviously make sense together like `Queue_Init()`, `Queue_GetSize()` than `queueInit()`, `getQueueSize()`, etc.

2. Comments with `#` preprocessing may not be portable 

        // #endif /* QUEUE_H_INCLUDED */
        /* QUEUE_H_INCLUDED */
        #endif

3. There is not _need_ for a `head` _and_ `tail`.  Alternative, only store `tail` and have the tail point to the head of the list.  End of list detected when `p->next == tail->next`.  This makes your head node one filed smaller.  Important if code uses _lots_ of queues.

4. Unclear why code uses `int` for the queue size type.  A signed type is not needed (could use `unsigned`) and on a system where `size_t` could be much wider than `int`, a queue size like `size_t` is more prudent.  Robust code would check for a queue exceed the max value of `size` in `enqueue()`.

5.  Good use of `size_t` for `memSize`.  Good error checking for `malloc()`.  Good to have test case.  IMO, a commented sample usage in the `*.h` file is nice. ; the `*.h` being the public interface to your good code.

6. Pedantic: Robust would check for `memSize==0` in `queueInit()` as that negates the correctness of the `malloc()` checks which should be `if(newNode == NULL && q->memSize > 0)`.

7. A little documentation goes a long way.  suggest a line or two of comment preceding each function declaration in `Queue.h`.

8.  Functions like `queuePeek(Queue *q, void *data)` that do not alter `*q` should be declared `queuePeek(const Queue *q, void *data)`.  This self documents the unchanging nature of `q` in the function to users and allows some optimizations a compiler may not otherwise employ.  It is a check on the implementation of the function too.

9.  For completeness, suggest `q->memSize = 0` in `clearQueue()`.

10.  Change `#include` order.  Put `"Queue.h"` _first_ as a check that `Queue.h` does not depend on the 3 `<*.h>` include files - unless that `.h` file is coded in `Queue.h`.

        #include "Queue.h"
        #include <stdio.h>
        #include <stdlib.h>
        #include <string.h>
        // #include "Queue.h"

11. Indicate failure.  If `void dequeue(Queue *q, void *data)` does not have anything in the queue to copy to `data`, there is no indication of that here.  Perhaps return `true/false` indicating success.  Same for `queuePeek()`.

12. For _debugging_,  zero filling memory before `free()` I have found useful.  Errant code tends to fail faster with a 0 pointer/data than with its original data still potentially intact.  Faster failing code is easier to debug. YMMV.